PRIVILEGED AND CONFIDENTIAL — ATTORNEY WORK PRODUCT
This memorandum was prepared by Calderwood & Harkness LLP in anticipation of litigation and/or in connection with the rendering of legal advice to Halcyon Semiconductor Aktiengesellschaft. This memorandum is protected by the attorney-client privilege, the work product doctrine, and other applicable privileges. Distribution of this memorandum, in whole or in part, to any person or entity other than those identified in the distribution list below, without the prior written consent of Calderwood & Harkness LLP, may constitute a waiver of applicable privileges.
DUE DILIGENCE MEMORANDUM — INTELLECTUAL PROPERTY
HALCYON SEMICONDUCTOR AG Prospective US Initial Public Offering via Level III ADR Program
Distribution:
Vivienne St. Claire, Partner, Capital Markets — Calderwood & Harkness LLP Robert Adeyemi, Partner, Capital Markets — Calderwood & Harkness LLP Leonard Cross, Counsel, Capital Markets — Calderwood & Harkness LLP Claire Dempsey, Lead Associate, Capital Markets — Calderwood & Harkness LLP Audrey Zhou, Working Associate, Capital Markets — Calderwood & Harkness LLP
Coordination copies available to Wilhelm Ostermann (General Counsel / Chefjustitiar, Halcyon Semiconductor AG) upon request.
This memorandum has been prepared in anticipation of the filing of a Registration Statement on Form F-1 under the Securities Act of 1933, as amended, in connection with the initial public offering of American Depositary Shares representing ordinary shares of Halcyon Semiconductor Aktiengesellschaft.
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I. EXECUTIVE SUMMARY
A. Purpose and Scope
This memorandum summarizes the intellectual property due diligence conducted by Calderwood & Harkness LLP in connection with the prospective initial public offering in the United States of Halcyon Semiconductor AG ("Halcyon" or the "Company") through a Level III American Depositary Receipt ("ADR") program. The contemplated offering targets gross proceeds of approximately $900,000,000 through the issuance and sale of American Depositary Shares ("ADSs"), each representing one ordinary share (Stammaktie) of Halcyon, with registration on Form F-1 under the Securities Act of 1933, as amended (the "Securities Act"), and listing of the ADSs on the Nasdaq Global Select Market under the proposed ticker symbol "HCYN." The depositary for the ADR program is expected to be Greaves Bancorp, and the underwriting syndicate is led by Ashford Bancorp and Pinnacle Capital Markets as joint bookrunning managers.
The scope of this memorandum encompasses the review and assessment of: (i) Halcyon's worldwide patent portfolio, including patents and patent applications related to silicon carbide ("SiC") and gallium nitride ("GaN") power semiconductor technologies; (ii) Halcyon's trade secret and proprietary know-how protection programs; (iii) Halcyon's trademark portfolio and domain name registrations; (iv) material intellectual property licensing agreements to which Halcyon or its subsidiaries are a party, including inbound licenses, outbound licenses, cross-license agreements, and joint development agreements; (v) freedom-to-operate considerations; (vi) pending and threatened intellectual property litigation; (vii) export control and sanctions considerations as they relate to Halcyon's intellectual property; and (viii) recommended disclosures for the Form F-1 prospectus.
B. Documents and Information Reviewed
Our review is based upon documents and information produced by Halcyon and its subsidiaries pursuant to the comprehensive Due Diligence Request List circulated on January 27, 2026, to Halcyon, its in-house legal department, and Bähr Stein Rechtsanwälte (Dr. Christoph Maurelban, Partner; Johanna Weiß, Senior Associate), German counsel to Halcyon. Documents were made available through the Company's virtual data room hosted on Thackeray Solutions (the "Data Room"), supplemented by management presentations and responses to supplemental information requests. We have also conducted searches of patent and trademark databases in the United States, European Union, Germany, People's Republic of China, Japan, and South Korea, as well as litigation docket searches across applicable jurisdictions. A complete list of documents reviewed is set forth in Appendix E to this memorandum.
We note that our review is necessarily limited to the documents and information made available to us. We have not independently verified the accuracy or completeness of the information provided by Halcyon or its advisors, and certain document requests remain outstanding as of the date of this memorandum, as described in Section X below. The opinions and assessments expressed herein are subject to updating as additional information becomes available.
C. Company Overview
Halcyon Semiconductor AG is an Aktiengesellschaft (stock corporation) incorporated under the laws of the Federal Republic of Germany, with its registered seat in Munich, Germany (Commercial Register Number HRB 217458, Amtsgericht München). Halcyon was founded in 1997 by Dr. Marcus Helder and Prof. Dr. Annika Roth and is a leading designer and manufacturer of advanced power semiconductor devices, with particular expertise in silicon carbide (SiC) and gallium nitride (GaN) chip technologies for applications in the automotive, industrial, and renewable energy sectors. As of the date of this memorandum, the Company employs approximately 8,400 employees worldwide across its principal facilities in Munich (headquarters and R&D center), Dresden (fabrication facilities Fab 2 and Fab 3, the latter currently under construction), Santa Clara, California (US design center), Shanghai (PRC design and applications engineering center), Singapore (regional sales and applications support), and Brno, Czech Republic (automotive components assembly).
For its fiscal year ended December 31, 2025, Halcyon reported unaudited consolidated revenue of approximately €3.82 billion, representing year-over-year growth of approximately 19%, driven primarily by strong demand for SiC power modules in electric vehicle ("EV") powertrains and renewable energy inverter applications. Capital expenditures for FY2025 were approximately €820 million, a significant portion of which was directed toward the expansion of SiC fabrication capacity at Fab 3 in Dresden.
D. Key Findings Summary
Based on our review, the key findings of the intellectual property due diligence are as follows:
Patent Portfolio. Halcyon maintains a substantial and strategically important worldwide patent portfolio concentrated in SiC and GaN power semiconductor technologies. The portfolio includes 2,847 granted patents and 1,214 pending patent applications across key jurisdictions including Germany, the European Patent Office, the United States, the People's Republic of China, Japan, and South Korea. The portfolio is well-structured around core technology families, with strong coverage of Halcyon's principal product lines and manufacturing processes. Near-term patent expirations are manageable and generally relate to earlier-generation technologies that have been superseded by newer designs.
Trade Secrets. Halcyon has implemented a trade secret protection program encompassing physical security, IT security, employee confidentiality obligations, and contractor nondisclosure agreements. However, certain documentation enhancements are recommended, particularly with respect to the formalization of a global trade secret policy and the cataloging of trade secrets associated with the Fab 3 facility under construction. Trade secret protection at the PRC subsidiary (Halcyon Shanghai Semiconductor Co., Ltd.) presents heightened risk that warrants specific prospectus risk factor disclosure.
Trademarks. The trademark portfolio adequately protects Halcyon's brand identity across key jurisdictions. All material trademark registrations are active and current. We recommend certain supplemental filings in the United States in connection with new product lines to be launched in connection with the IPO.
IP Licensing Agreements. Halcyon's IP licensing arrangements are generally favorable, with manageable third-party dependencies. Our review of change-of-control and assignment provisions in material inbound licenses indicates that the proposed IPO transaction — which involves the issuance of new ordinary shares and the establishment of an ADR program but does not constitute a change of control of Halcyon — should not trigger consent or termination rights under the material agreements reviewed. Certain cross-license arrangements with other semiconductor companies contain defensive aggregation provisions that require further analysis, as discussed in Section V.C below.
IP Litigation. intellectual property litigation exposure is moderate and manageable for prospectus disclosure purposes. There are currently three pending IP litigation matters involving Halcyon or its subsidiaries, as described in Section VII below, none of which is expected to result in a material adverse effect on the Company's business, financial condition, or results of operations.
Export Controls. Certain of Halcyon's proprietary technologies are subject to export control restrictions under the US Export Administration Regulations and the EU Dual-Use Regulation. The Company has implemented an export compliance program, although deemed export considerations associated with technology transfers involving the PRC subsidiary require ongoing monitoring. This topic is addressed in greater detail in the separate Due Diligence Memorandum — Sanctions, Anti-Corruption, and Export Controls (Matter No. 1032-00003-SC), and we provide a summary of IP-specific considerations in Section VIII below.
E. Subsidiaries with IP Holdings
The following Halcyon entities hold intellectual property relevant to this memorandum:
1. Halcyon Semiconductor AG (Munich, Germany) — Principal patent and trademark holder. Owns the majority of the Company's worldwide patent portfolio, all principal trademark registrations, and the core technology know-how.
2. Halcyon Power Solutions GmbH (Dresden, Germany) — A wholly owned subsidiary of Halcyon Semiconductor AG. Holds manufacturing process intellectual property associated with Fab 2 (operational) and Fab 3 (under construction). Certain process patents relating to SiC wafer fabrication and epitaxial deposition are registered in the name of this entity.
3. Halcyon Semiconductor USA Inc. (incorporated in Delaware; principal office at 2500 Augustine Drive, Suite 100, Santa Clara, CA 95054) — A wholly owned subsidiary of Halcyon Semiconductor AG. Holds certain US patent filings developed at the Santa Clara design center, as well as US-developed application engineering intellectual property, software tools, and design libraries.
4. Halcyon Shanghai Semiconductor Co., Ltd. (Shanghai, PRC) — A wholly foreign-owned enterprise and wholly owned subsidiary of Halcyon Semiconductor AG. Holds a limited number of PRC design patents for localized products developed for the Chinese market, as well as certain software copyrights registered with the National Copyright Administration of China.
5. Halcyon Asia Pacific Pte. Ltd. (Singapore) — Does not directly hold registered intellectual property but employs applications engineers who contribute to the development of customer-specific design solutions. Intellectual property developed by Singapore-based employees is assigned to Halcyon Semiconductor AG pursuant to intercompany intellectual property assignment agreements.
6. Halcyon Automotive Components s.r.o. (Brno, Czech Republic) — A wholly owned subsidiary engaged in automotive power module assembly. Does not hold registered intellectual property, but possesses manufacturing process know-how related to module assembly and testing.
F. Key Personnel Consulted
In connection with this due diligence review, we conducted interviews and management presentations with the following key Halcyon personnel:
• Dr. Marcus Helder — Chief Technology Officer and co-founder. PhD in Material Science, ETH Zürich (1994). Dr. Helder oversees all technology development and is the named inventor on more than 120 Halcyon patent families. Dr. Helder provided the principal management presentations on Halcyon's technology roadmap, patent strategy, and competitive positioning.
• Wilhelm Ostermann — General Counsel / Chefjustitiar. Mr. Ostermann coordinated the production of IP-related documents and information and served as the primary liaison for IP due diligence matters.
• Dr. Sabine Falkner — Head of intellectual Property, Halcyon Semiconductor AG. Dr. Falkner oversees the in-house IP department, including patent prosecution, trademark management, and trade secret protection programs.
• Rajesh Venkatesan — Vice President, Engineering, Halcyon Semiconductor USA Inc. Mr. Venkatesan provided information regarding US-developed intellectual property and the Santa Clara design center operations.
II. PATENT PORTFOLIO
A. Overview of Patent Holdings
Halcyon's patent portfolio is central to the Company's competitive position in the power semiconductor industry. Based on our review of the Company's IP register (produced as Data Room document HCS-IP-001 through HCS-IP-047) and independent searches conducted in the relevant patent databases, we summarize the patent holdings as follows.
Aggregate Patent Holdings. As of the date of this memorandum, Halcyon and its subsidiaries collectively hold 2,847 granted patents and 1,214 pending patent applications worldwide. The portfolio is organized into approximately 682 distinct patent families, reflecting the Company's practice of filing patent applications in multiple jurisdictions for significant inventions. The core portfolio is concentrated in the following technology areas:
(a) Power semiconductor device architectures, including SiC MOSFET, SiC Schottky barrier diode, SiC IGBT, GaN HEMT, and GaN-based power conversion circuit topologies;
(b) SiC crystal growth and epitaxy processes, including physical vapor transport (PVT) growth methods, SiC boule slicing and polishing techniques, and chemical vapor deposition (CVD) epitaxial layer deposition;
(c) GaN-on-SiC and GaN-on-Si device structures, including buffer layer engineering, gate dielectric processes, and normally-off device architectures;
(d) Packaging and thermal management solutions, including direct-bonded copper (DBC) substrates, sintered silver die-attach processes, double-sided cooling module designs, and embedded packaging for high-power-density applications;
(e) Automotive-grade reliability testing methodologies, including high-temperature reverse bias (HTRB) testing innovations, power cycling test structures, and accelerated lifetime prediction models; and
(f) Power module integration technologies, including multi-chip module architectures, intelligent power module (IPM) designs, and gate driver integration.
Jurisdictions of Patent Filings. Halcyon's patent filing strategy targets the principal semiconductor manufacturing and consumption markets worldwide. Patent filings have been made in the following jurisdictions and before the following authorities:
(a) Germany — Deutsches Patent- und Markenamt ("DPMA");
(b) European Patent Office ("EPO") — including designations in Germany, France, Italy, the Netherlands, Austria, Sweden, Finland, and the United Kingdom (pre-Brexit filings validated in the UK);
(c) United States — United States Patent and Trademark Office ("USPTO");
(d) People's Republic of China — China National intellectual Property Administration ("CNIPA");
(e) Japan — Japan Patent Office ("JPO");
(f) South Korea — Korean intellectual Property Office ("KIPO"); and
(g) Patent Cooperation Treaty ("PCT") — international applications filed under the PCT, with national phase entries in the jurisdictions listed above.
The following table summarizes the distribution of Halcyon's patent holdings by jurisdiction:
Patent Ownership Structure. The majority of Halcyon's patent portfolio — comprising approximately 2,190 granted patents and 923 pending applications — is owned directly by Halcyon Semiconductor AG. The remaining patents are distributed among the Company's subsidiaries as follows:
(a) Halcyon Semiconductor USA Inc. — 384 granted US patents and 197 pending US patent applications. These patents relate primarily to application engineering designs, power conversion circuit topologies, and gate driver innovations developed at the Santa Clara design center. In addition, 47 granted patents and 18 pending applications are co-owned by Halcyon Semiconductor AG and Halcyon Semiconductor USA Inc. as a result of collaborative development activities between the Munich and Santa Clara teams. We note that the co-ownership of US patents raises certain considerations under US patent law (35 U.S.C. § 262), as each co-owner may independently exploit the patent without accounting to the other co-owner absent a written agreement to the contrary. We have reviewed the intercompany IP agreements between Halcyon Semiconductor AG and Halcyon Semiconductor USA Inc. and confirm that these agreements appropriately address co-ownership rights through an intercompany license and coordination mechanism.
(b) Halcyon Power Solutions GmbH — 218 granted patents (primarily German and EPO patents) and 72 pending applications relating to manufacturing process innovations developed at the Dresden fabrication facilities. These include patents covering SiC wafer processing steps, clean room equipment configurations, and epitaxial layer uniformity control techniques.
(c) Halcyon Shanghai Semiconductor Co., Ltd. — 55 granted PRC design patents and 24 pending applications for localized product designs. These design patents cover specific package configurations and form factors developed for the Chinese automotive and industrial markets. We note that the scope of protection afforded by PRC design patents is more limited than that afforded by invention patents, as design patents protect only the ornamental aspects of a product and have a 15-year term from the filing date.
Internal Patent Management. Halcyon's patent portfolio is managed by an in-house IP department consisting of 14 professionals, including 6 patent attorneys (Patentanwälte), 4 patent engineers, and 4 administrative and paralegal staff. The IP department reports to Dr. Marcus Helder (CTO), with legal oversight provided by Wilhelm Ostermann (General Counsel). For patent prosecution in jurisdictions outside of Germany and Europe, Halcyon engages a network of external patent counsel, including Firth & Ashford LLP (US patent prosecution), Ostrander & Voss LLP (Japan), and Severin & Quill LLP (South Korea). Patent annuity management is outsourced to Kestrel Technologies, a third-party patent management service provider.
B. SiC Patent Portfolio
Description. Halcyon's SiC-related patent portfolio is the largest and most strategically significant component of the Company's overall patent holdings. SiC technology forms the foundation of Halcyon's automotive and renewable energy product lines, which together accounted for approximately 67% of the Company's FY2025 revenue. The SiC patent portfolio encompasses the following principal technology areas:
(a) SiC Substrate Growth Techniques — Patents covering Halcyon's proprietary physical vapor transport (PVT) crystal growth methods for producing high-purity, low-defect-density 150mm and 200mm SiC substrates. Key innovations include seed crystal selection and preparation methods, temperature gradient control techniques, and in-situ defect monitoring systems.
(b) SiC Epitaxial Layer Deposition — Patents covering chemical vapor deposition (CVD) processes for depositing SiC epitaxial layers with controlled doping profiles, thickness uniformity, and surface morphology. These patents are particularly important for the production of high-voltage SiC devices (1200V and above) used in EV traction inverters.
(c) SiC MOSFET and Diode Device Structures — Patents covering Halcyon's proprietary SiC MOSFET cell designs, including planar and trench gate architectures, channel mobility enhancement techniques, gate oxide reliability improvements, and integrated body diode optimization. The portfolio also includes patents on SiC Schottky barrier diode and junction barrier Schottky (JBS) diode structures.
(d) Edge Termination Designs — Patents covering guard ring, junction termination extension (JTE), and field plate edge termination structures optimized for SiC high-voltage devices.
(e) SiC Module Packaging — Patents covering advanced packaging technologies for SiC power modules, including double-sided cooling designs, sintered interconnect technologies, and high-temperature-capable encapsulation materials.
Active SiC Patents and Pending Applications. The SiC patent portfolio comprises 1,437 granted patents and 584 pending applications across the key jurisdictions identified above, organized into approximately 318 patent families. Of these, approximately 142 patent families are considered by Halcyon's IP department to be "Tier 1" — that is, patents that directly protect current product architectures and manufacturing processes in active commercial production.
Key Patent Families and Representative Claims. We have reviewed in detail the 25 highest-priority SiC patent families identified by Dr. Sabine Falkner (Head of IP). Without reproducing the specific claim language in this memorandum for confidentiality reasons, we note that the claims in the key families are generally well-drafted, with independent claims of appropriate scope and dependent claims providing fallback positions. Several families include both device claims (directed to the SiC semiconductor device structure itself) and method claims (directed to the process of manufacturing the device), providing complementary protection. Representative key families include:
(i) The "Halcyon Trench MOSFET" family (EP Patent No. 2,XXX,XXX; US Patent Nos. 10,XXX,XXX and 11,XXX,XXX; and counterparts in CN, JP, and KR), covering Halcyon's proprietary SiC trench MOSFET architecture, which is the core device structure used in Halcyon's flagship HCY-1200T product series;
(ii) The "Low-Defect SiC Substrate" family (EP Patent No. 3,XXX,XXX; US Patent No. 11,XXX,XXX; and counterparts), covering Halcyon's advanced PVT crystal growth methodology, which enables the production of SiC substrates with micropipe density below 0.1/cm²; and
(iii) The "Double-Sided Cooling Module" family (EP Patent No. 3,XXX,XXX; US Patent No. 10,XXX,XXX; and counterparts), covering Halcyon's proprietary SiC power module packaging architecture used in automotive traction inverter applications.
Remaining Patent Terms and Expiration Schedule. The SiC patent portfolio has a generally favorable remaining term profile. The weighted-average remaining term of the Tier 1 SiC patent families is approximately 11.3 years. The earliest expirations within the Tier 1 portfolio occur in 2030 (affecting 8 patent families, primarily relating to first-generation planar SiC MOSFET designs that have been substantially superseded by Halcyon's current trench MOSFET architecture). The core trench MOSFET and advanced substrate families, which protect Halcyon's current and next-generation products, have remaining terms extending through 2038–2043. The Fab 3 expansion manufacturing process patents, which protect Halcyon's most advanced fabrication techniques, have particularly long remaining terms, as many were filed within the last five years.
We have identified 23 SiC patent families (encompassing 87 granted patents across jurisdictions) with expiration dates occurring within the next five years (i.e., by February 2031). Of these, the Company's IP department has confirmed that 19 families relate to earlier-generation technology that has been superseded by newer designs and whose expiration is not expected to have a material adverse effect on Halcyon's competitive position. The remaining 4 families relate to edge termination techniques and certain substrate processing steps that continue to be used in current production. However, Dr. Helder has confirmed that these techniques are supplemented by additional patented and trade-secret-protected innovations that provide continued competitive protection.
Geographic Coverage Analysis. The SiC patent portfolio provides robust protection in all of the key semiconductor markets. Coverage is strongest in Germany, the broader EU (via EPO grants), and the United States, which together account for the majority of Halcyon's SiC product sales. Coverage in the PRC, Japan, and South Korea is generally adequate for Halcyon's principal SiC product lines, although we note that certain earlier patent families were not filed in South Korea due to a prior patent filing strategy that gave lower priority to that jurisdiction. Halcyon's IP department has confirmed that more recent patent families (filed from 2018 onward) include South Korea as a standard filing jurisdiction, and we consider the current coverage to be adequate for the Company's current and anticipated business activities.
Strategic Importance. The strategic importance of the SiC patent portfolio cannot be overstated. SiC technology is the cornerstone of Halcyon's automotive and renewable energy product lines, which collectively represent the Company's largest and fastest-growing business segments. A significant portion of the Company's €820 million FY2025 capital expenditure was directed at expanding SiC fabrication capacity, including the construction of Fab 3 in Dresden, which is expected to receive approximately $280,000,000 of the net proceeds from the IPO. The SiC patent portfolio provides the intellectual property protection necessary to secure the return on this substantial capital investment.
C. GaN Patent Portfolio
Description. Halcyon's GaN-related patent portfolio covers the Company's growing portfolio of gallium nitride power semiconductor technologies. While smaller than the SiC portfolio, the GaN portfolio represents an area of significant strategic investment and growth potential. The GaN patent portfolio encompasses the following principal technology areas:
(a) GaN Epitaxial Growth — Patents covering gallium nitride epitaxial growth on various substrates, including GaN-on-SiC (used for higher-power applications) and GaN-on-Si (used for cost-sensitive applications). Key innovations include buffer layer engineering to manage lattice mismatch and thermal expansion differences, as well as proprietary metalorganic chemical vapor deposition (MOCVD) process recipes.
(b) GaN HEMT Device Architectures — Patents covering Halcyon's proprietary GaN high electron mobility transistor (HEMT) device structures, including enhancement-mode (normally-off) GaN HEMT designs using p-type GaN gate technology and recessed gate structures.
(c) Gate Driver Integration — Patents covering integrated gate driver circuits optimized for GaN power devices, including high-speed gate driver designs that exploit the fast switching capability of GaN transistors.
(d) Power Conversion Circuits — Patents covering power conversion circuit topologies (e.g., half-bridge, full-bridge, and multi-level converter configurations) optimized for use with GaN power devices.
Active GaN Patents and Pending Applications. The GaN patent portfolio comprises 612 granted patents and 347 pending applications across key jurisdictions, organized into approximately 164 patent families. The portfolio is younger than the SiC portfolio, reflecting the more recent development timeline for Halcyon's GaN technology program, with the majority of patent families having been filed since 2016.
Key Patent Families and Representative Claims. The most significant GaN patent families include:
(i) The "Enhancement-Mode GaN HEMT" family (EP Patent No. 3,XXX,XXX; US Patent No. 11,XXX,XXX; and counterparts), covering Halcyon's proprietary p-GaN gate normally-off HEMT architecture;
(ii) The "GaN-on-Si Buffer Layer" family (US Patent No. 11,XXX,XXX; CN Patent No. ZL 2019 X XXXX,XXX.X; and counterparts), covering Halcyon's multi-step buffer layer growth process that enables high-quality GaN device fabrication on large-diameter silicon substrates; and
(iii) The "High-Speed GaN Gate Driver" family (US Patent No. 12,XXX,XXX; EP Application No. 22XXX,XXX.X; and counterparts), covering Halcyon's integrated gate driver solution with sub-nanosecond switching transitions.
Remaining Patent Terms and Expiration Schedule. Due to the relatively recent filing dates of the GaN portfolio, the weighted-average remaining term is approximately 15.8 years. No material GaN patents are expected to expire within the next eight years. This favorable term profile aligns well with Halcyon's long-term GaN technology development roadmap.
Strategic Importance. GaN technology represents a key growth area for Halcyon, particularly in the data center power supply, telecommunications, and consumer fast-charging markets. The Company has allocated $140,000,000 of the anticipated IPO net proceeds to research and development of next-generation GaN power devices, including 200V-rated GaN-on-Si devices for high-frequency power conversion and GaN-on-SiC devices for higher-power applications. The GaN patent portfolio provides a foundation for protecting the Company's anticipated R&D investment and future product launches.
D. Other Patent Categories
In addition to the SiC and GaN portfolios described above, Halcyon holds patents in the following categories:
Packaging and Thermal Management Patents. Halcyon holds 389 granted patents and 143 pending applications (approximately 98 patent families) relating to advanced power semiconductor packaging and thermal management technologies. These patents cover innovations in direct-bonded copper (DBC) and active metal brazed (AMB) substrates, sintered silver and sintered copper die-attach processes, wire bond and ribbon bond interconnect technologies, double-sided and embedded cooling module architectures, and high-temperature-capable encapsulant and molding compound formulations. The packaging patent portfolio spans both SiC and GaN product applications and is increasingly important as the industry moves toward higher power densities.
Test and Reliability Methodology Patents. Halcyon holds 178 granted patents and 62 pending applications (approximately 49 patent families) relating to semiconductor reliability testing methodologies. These patents cover innovations in high-temperature reverse bias (HTRB) testing, high-temperature gate bias (HTGB) testing, power cycling test equipment and procedures, and accelerated lifetime prediction models for power semiconductor devices. While these patents are not directly embodied in Halcyon's end products, they protect proprietary test infrastructure and methodologies that contribute to the Company's reputation for automotive-grade quality and reliability.
Power Module Integration Patents. Halcyon holds 143 granted patents and 51 pending applications (approximately 35 patent families) relating to power module integration technologies, including multi-chip module architectures, intelligent power module (IPM) designs incorporating integrated signal processing and protection functions, and hybrid SiC/Si module configurations for cost-optimized automotive applications.
Automotive-Specific Application Patents. Halcyon holds 88 granted patents and 27 pending applications (approximately 18 patent families) relating to automotive-specific innovations, including functional safety architectures compliant with ISO 26262, redundant sensing and monitoring circuits for traction inverter applications, and on-chip diagnostic features for predictive maintenance systems.
E. Patent Prosecution Status
We have reviewed the prosecution status of Halcyon's pending patent applications worldwide based on the patent prosecution status report provided by Dr. Sabine Falkner (Data Room document HCS-IP-048) and independent docket searches. A summary of the prosecution status is as follows:
Outstanding Office Action Responses. Of the 189 applications for which office action responses are pending, 34 have response deadlines falling within the next 60 days. Halcyon's IP department has confirmed that responses are in preparation for all applications with near-term deadlines. We have reviewed a sample of 12 pending office actions (4 USPTO, 3 EPO, 3 CNIPA, 2 JPO) and their proposed responses, and we assess the prosecution positions taken to be reasonable and well-supported.
Assessment of Prosecution Risks. Based on our review of the pending prosecution matters, we assess the overall prosecution risk as moderate and consistent with industry norms for a patent portfolio of this size and technological complexity. The primary prosecution risk areas include: (i) potential narrowing of claims in 11 USPTO applications in the GaN HEMT technology area, where the examiner has cited prior art from Sundial Holdings and Ridgeway Industries; (ii) protracted prosecution of 8 CNIPA applications relating to SiC substrate growth techniques, where Chinese examination practice tends to impose more restrictive novelty and inventive step requirements; and (iii) potential divisional requirements in 5 EPO applications where unity of invention objections have been raised.
PCT Applications and National Phase Entry Deadlines. There are currently 74 PCT international applications in the international phase. Of these, 12 applications have national phase entry deadlines within the next 90 days (the 30-month deadline from the priority date under PCT Article 22). Halcyon's IP department has confirmed that national phase entry instructions have been or will be issued for all applications in a timely manner. The national phase entry strategy for each application has been reviewed and approved by the relevant technology area lead within the IP department.
F. Patent Maintenance and Annuity Status
Maintenance Fee and Annuity Status. Based on our review of the annuity management reports provided by Kestrel Technologies (Data Room document HCS-IP-049), we confirm that all maintenance fees and annuities for material patents in the Halcyon portfolio are current as of February 15, 2026. Calderon Technologies provides Halcyon with quarterly reconciliation reports, and Halcyon's IP department conducts an annual internal audit of the annuity payment records. The most recent annual audit was completed in November 2025 with no discrepancies identified.
Lapsed Patents. Calderon Technologies's records indicate that 23 patents across the portfolio lapsed during the period from January 2023 to January 2026 due to deliberate non-payment of annuities as part of Halcyon's periodic portfolio pruning process. Each of these lapsed patents was the subject of an internal assessment by the IP department and approved for abandonment by the relevant technology area lead. We have reviewed the abandonment assessments for these 23 patents and confirm that none is considered material to Halcyon's current or planned business activities. No patents have lapsed inadvertently during the review period.
Third-Party Patent Management Service Provider. As noted above, Halcyon's patent annuity management is outsourced to Kestrel Technologies (Luxembourg). The engagement is governed by a services agreement dated March 14, 2019, which provides for standard terms regarding accuracy, liability, and reporting. We have reviewed this agreement and note no unusual terms or concerns.
III. TRADE SECRETS AND PROPRIETARY KNOW-HOW
A. Overview of Trade Secret Program
Trade secrets and proprietary know-how represent a critical component of Halcyon's intellectual property portfolio and, in many respects, provide the Company's most important competitive moats. While patents provide time-limited exclusivity for disclosed inventions, Halcyon's trade secrets — which encompass process know-how, recipes, and operational parameters accumulated over more than 25 years of semiconductor manufacturing — are not subject to expiration and in some cases are more difficult for competitors to replicate than the patented technology they complement.
The principal categories of trade secrets maintained by Halcyon include:
(a) SiC Crystal Growth Process Parameters — Detailed process recipes for physical vapor transport (PVT) growth of SiC boules, including temperature profiles, pressure schedules, gas flow rates, seed crystal preparation techniques, and quality control parameters. These process recipes represent the accumulated know-how of more than two decades of SiC crystal growth development and are not disclosed in Halcyon's patent filings (which claim the general methods but do not disclose the specific operational parameters necessary to achieve production-quality results).
(b) GaN Epitaxial Recipes — Proprietary MOCVD recipes for gallium nitride epitaxial growth on SiC and Si substrates, including precursor flow rates, chamber temperature profiles, growth rates, and buffer layer sequences.
(c) Proprietary Fabrication Process Flows — Detailed fabrication process flows for the production of SiC and GaN devices at Fab 2 (Dresden) and Fab 3 (under construction, Dresden), including photolithography masks sets, ion implantation recipes, oxidation schedules, and metallization processes.
(d) Device Design Databases — Proprietary device design databases containing TCAD simulation models, device layout libraries, process design kits (PDKs), and parametric cell libraries developed by Halcyon's design engineering teams.
(e) Test Methodologies — Proprietary reliability test procedures, qualification protocols, and failure analysis techniques not disclosed in Halcyon's published standards or patent filings.
(f) Yield Optimization Algorithms — Proprietary algorithms and machine learning models used for yield optimization, defect detection, and statistical process control in Halcyon's fabrication facilities.
(g) Customer-Specific Design Specifications — Confidential design specifications developed in connection with custom or semi-custom product development programs for automotive OEM customers.
Importance to Competitive Position. The importance of trade secrets to Halcyon's competitive position is particularly pronounced in the area of SiC crystal growth and epitaxial processing. The semiconductor industry widely recognizes that the production of high-quality SiC substrates is as much a matter of accumulated process know-how as it is of patented technology. Halcyon's ability to produce 200mm SiC substrates with micropipe densities below 0.1/cm² is a significant competitive differentiator, and the specific process parameters required to achieve this result are maintained as closely guarded trade secrets. Similarly, Halcyon's fabrication yields — which are understood to be among the highest in the industry for SiC power devices — are attributable in large part to proprietary process control and yield optimization know-how that is not publicly disclosed.
B. Trade Secret Protection Measures
We have reviewed Halcyon's trade secret protection measures across its principal facilities and operations, as summarized below.
Physical Security. Halcyon maintains multi-layered physical security controls at its fabrication and R&D facilities:
(a) Munich Headquarters and R&D Center — Access to the R&D center and design laboratories is controlled by badge-based electronic access systems with biometric (fingerprint) authentication for designated restricted areas. The facility is monitored by 24/7 security personnel and closed-circuit television surveillance. Visitor access to R&D areas requires prior authorization and escort.
(b) Halcyon Power Solutions GmbH, Dresden (Fab 2 and Fab 3 site) — The Dresden fabrication facilities employ semiconductor-industry-standard cleanroom access controls, including gowning and badging requirements, zone-restricted access based on job function, and electronic logging of all facility entries and exits. The Fab 3 construction site is secured by perimeter fencing, construction site access controls, and contractual confidentiality obligations with all construction contractors.
(c) Halcyon Automotive Components s.r.o., Brno — The Brno assembly facility employs badge-based access controls and visitor management protocols consistent with automotive industry supply chain security requirements.
(d) Halcyon Semiconductor USA Inc., Santa Clara — The Santa Clara design center employs badge-based access controls and physically separated design laboratory spaces with restricted access.
(e) Halcyon Shanghai Semiconductor Co., Ltd., Shanghai — The Shanghai facility employs badge-based access controls, visitor management protocols, and CCTV surveillance. We note, however, that the physical security measures at the Shanghai facility are somewhat less robust than those at the Munich and Dresden facilities, and we recommend certain enhancements as discussed in Section III.C below.
IT Security. Halcyon's IT security program for the protection of electronic trade secret information includes the following principal measures:
(a) Encryption of sensitive design databases and process recipe files at rest (AES-256) and in transit (TLS 1.3);
(b) Role-based access controls (RBAC) for all design tools, simulation environments, and process recipe databases, with access privileges assigned based on job function and reviewed quarterly;
(c) Network segmentation separating the corporate network from the fabrication operational technology (OT) network and the design engineering network;
(d) Data loss prevention (DLP) systems monitoring for unauthorized transmission of sensitive files via email, removable media, or cloud storage services;
(e) Endpoint detection and response (EDR) solutions deployed on all engineering workstations;
(f) Regular penetration testing conducted by an external cybersecurity firm (most recent test completed October 2025, with no critical vulnerabilities identified); and
(g) An incident response plan for cybersecurity and trade secret incidents, tested annually through tabletop exercises.
Employee Obligations. Halcyon's standard employment agreements contain confidentiality and intellectual property assignment provisions. We have reviewed sample employment agreements for each of the jurisdictions in which Halcyon employs engineering personnel (Germany, United States, PRC, Czech Republic, and Singapore) and note the following:
(a) German Employment Agreements — Halcyon's standard German employment agreement (reviewed by Bähr Stein Rechtsanwälte and confirmed by Johanna Weiß) includes confidentiality provisions that survive the termination of employment. Under German law, the duty of confidentiality during employment arises by operation of law (§ 17 UWG) and under the employment contract; post-employment confidentiality is governed by the contractual provisions and, to a limited extent, by statutory trade secret protection under the German Trade Secrets Act (Geschäftsgeheimnisgesetz — GeschGehG), which implements the EU Trade Secrets Directive (EU) 2016/943. German employment agreements also provide for post-employment non-competition covenants (nachvertragliches Wettbewerbsverbot) with durations of up to 24 months, subject to the mandatory requirement under § 74 HGB that the employer pay compensation (Karenzentschädigung) of at least 50% of the employee's last drawn remuneration during the non-compete period. Bähr Stein has confirmed that Halcyon's non-compete provisions comply with the requirements of § 74 et seq. HGB, and that Halcyon has consistently paid the required Karenzentschädigung to departing employees subject to non-competes.
(b) US Employment Agreements — Halcyon Semiconductor USA Inc.'s standard employment agreements include confidentiality, invention assignment, and non-solicitation provisions. Non-compete provisions are included for employees at the senior engineer level and above, subject to compliance with California Business and Professions Code § 16600 (which, as of January 1, 2024, has been further clarified by AB 1076 and SB 699 to broadly prohibit non-compete agreements with California employees). Accordingly, non-compete provisions in the employment agreements of California-based employees are not enforceable, and the Company relies on confidentiality, invention assignment, and non-solicitation provisions as the primary contractual protections. Halcyon Semiconductor USA Inc. also utilizes a Proprietary Information and Inventions Agreement (PIIA) that all employees are required to execute upon hire.
(c) PRC Employment Agreements — Halcyon Shanghai Semiconductor Co., Ltd.'s employment agreements include confidentiality and non-compete provisions in accordance with PRC Labor Contract Law. Non-compete provisions are limited to two years and require payment of compensation during the non-compete period. We note, however, that enforcement of non-compete and confidentiality obligations in the PRC remains challenging in practice, and we have identified certain recommendations for enhancement in Section III.C below.
Contractor and Consultant Agreements. Halcyon engages independent contractors and consultants in connection with specialized engineering projects, equipment installation, and IT services. We have reviewed a sample of contractor and consultant agreements and confirm that they contain nondisclosure and, where applicable, intellectual property assignment provisions. However, we note that certain legacy contractor agreements (pre-2019) do not contain express work-for-hire or assignment provisions with respect to intellectual property developed in the course of the engagement, and we recommend that these agreements be updated in connection with any ongoing engagements.
Subsidiary-Level Trade Secret Protections. We have conducted a subsidiary-level assessment of trade secret protections, with particular attention to the following:
(a) Halcyon Shanghai Semiconductor Co., Ltd. — The PRC subsidiary operates in a heightened risk environment for trade secret protection. While PRC trade secret law has been strengthened in recent years (particularly through amendments to the Anti-Unfair Competition Law effective April 2019 and the establishment of specialized IP courts), enforcement remains challenging and the risk of trade secret misappropriation is elevated. We note that the Shanghai facility has access to certain design databases and application engineering tools through the Company's IT network, and that data transfer between the Shanghai facility and the Munich and Dresden facilities occurs on a regular basis. The Company has implemented data access controls and network segmentation to limit the scope of information accessible from the Shanghai facility, but we recommend that Halcyon conduct a comprehensive review of the data accessible from the PRC subsidiary and implement additional access restrictions where appropriate.
(b) Halcyon Asia Pacific Pte. Ltd., Singapore — The Singapore subsidiary employs applications engineers who interact with customers across the Asia-Pacific region. Intellectual property developed by Singapore-based employees is assigned to Halcyon Semiconductor AG pursuant to intercompany assignment agreements. Singapore's trade secret protection framework, based on the common law duty of confidence and contractual provisions, is generally robust.
C. Recommendations
Based on our review of Halcyon's trade secret and proprietary know-how protection program, we make the following recommendations:
1. Formalize Global Trade Secret Policy. We recommend that Halcyon adopt a formalized global trade secret policy that meets the standards of the US Defend Trade Secrets Act of 2016 (18 U.S.C. § 1836 et seq.) and the EU Trade Secrets Directive (EU) 2016/943, as implemented by the German Geschäftsgeheimnisgesetz. The policy should include a clear definition of trade secret information, identification of "reasonable measures" for trade secret protection (consistent with the statutory requirements for trade secret status), employee and contractor acknowledgment procedures, and incident reporting protocols. This formalization is particularly important in connection with the US listing, as the DTSA provides a federal cause of action for trade secret misappropriation that requires the trade secret owner to demonstrate that it has taken "reasonable measures" to keep the information secret.
2. Enhance Trade Secret Cataloging for Fab 3. The Fab 3 facility currently under construction in Dresden will incorporate Halcyon's most advanced SiC fabrication process technology. We recommend that Halcyon implement a systematic trade secret identification and cataloging process for Fab 3, including documentation of all proprietary process recipes, equipment configurations, and process control parameters that are to be protected as trade secrets. This cataloging should be completed prior to the commencement of production at Fab 3.
3. Strengthen PRC Trade Secret Protections. We recommend that Halcyon conduct a comprehensive review of the data and information accessible from the Halcyon Shanghai Semiconductor Co., Ltd. facility, with a view to implementing additional access restrictions and data loss prevention measures. We further recommend that Halcyon engage local PRC counsel to review the current trade secret protection measures at the Shanghai facility and provide recommendations for enhancement under PRC law.
4. Update Legacy Contractor Agreements. We recommend that Halcyon review and update all active contractor and consultant agreements to ensure that they contain appropriate nondisclosure, work-for-hire, and intellectual property assignment provisions.
5. Prospectus Risk Factor Disclosure. We recommend that the Form F-1 prospectus include a risk factor addressing the challenges of protecting trade secrets and proprietary know-how, with specific reference to the risks associated with the Company's PRC operations.
IV. TRADEMARK PORTFOLIO
A. Overview of Trademark Registrations
Halcyon maintains a trademark portfolio that protects the Company's brand identity across key markets. The principal trademarks include:
(a) "HALCYON" — word mark, registered in all principal jurisdictions;
(b) "HALCYON SEMICONDUCTOR" — word mark, registered in Germany, the EU, the US, the PRC, Japan, and South Korea;
(c) Halcyon Corporate Logo Mark — a stylized "H" device mark incorporating a semiconductor die motif, registered in all principal jurisdictions;
(d) "HALCYON SiCPOWER" — product line mark for SiC power device products, registered in the EU and the US;
(e) "HALCYON GaNFAST" — product line mark for GaN power device products, registered in the EU, the US, and the PRC; and
(f) "HALCYON AUTOSAFE" — product line mark for automotive-grade power modules, registered in Germany, the EU, and the US.
Jurisdictions of Registration. Halcyon's trademark registrations span the following jurisdictions:
Trademark Ownership. All principal trademark registrations are owned by Halcyon Semiconductor AG. Halcyon's subsidiaries use the marks under informal, non-exclusive intra-group licenses. We recommend that the Company formalize these intra-group trademark license arrangements in writing to ensure enforceability and to support the Company's trademark rights against potential challenges of non-use or abandonment in certain jurisdictions.
Registration Status. We have confirmed, through a review of Halcyon's trademark docket (Data Room document HCS-IP-050) and independent searches of the relevant trademark registries, that all material trademark registrations are active and current. The next renewal deadline for a material trademark occurs on September 14, 2027 (EU Trade Mark Registration No. 012XXX471, "HALCYON" word mark), with sufficient lead time for the Company to file the renewal application.
B. Domain Names
Halcyon has registered the following key domain names:
(a) halcyon-semi.com — primary corporate website;
(b) halcyon-semiconductor.com — redirect to primary corporate website;
(c) halcyonsemi.de — German-language corporate website;
(d) halcyon-semi.cn — PRC corporate website;
(e) halcyon-semi.co.jp — Japan corporate website; and
(f) halcyon-semi.com.sg — Singapore corporate website.
All domain name registrations are current, with registrations managed through a centralized domain management account with a reputable registrar. Domain names are set to auto-renew. We recommend that Halcyon consider registering additional defensive domain names (e.g., halcyonsemiconductor.com, halcyon-semi.io) to protect against potential cybersquatting or brand dilution.
C. Trademark Enforcement History
Halcyon has been involved in the following trademark proceedings:
1. EUIPO Opposition No. B 003 XXX 127 (filed August 2022) — Halcyon Semiconductor AG v. Halcyonis GmbH (Munich, Germany). Halcyon successfully opposed the registration of the EU trademark "HALCYONIS" in Class 9 (semiconductor devices) on the grounds of likelihood of confusion with Halcyon's prior "HALCYON" EU trademark registration. The EUIPO Opposition Division ruled in Halcyon's favor in March 2023, and the decision was not appealed.
2. CNIPA Invalidation Action (filed February 2024) — Halcyon Semiconductor AG v. Shenzhen Harcyon Electronics Co., Ltd. Halcyon initiated an invalidation action against the PRC trademark registration for "HARCYON" in Class 9, filed by a Shenzhen-based entity. The matter remains pending before the CNIPA Trademark Review and Adjudication Board. Based on the strength of Halcyon's prior PRC registrations and the similarity of the marks, we assess a favorable outcome as probable.
We have not identified any other past or ongoing trademark opposition, cancellation, or infringement proceedings involving Halcyon. We have conducted clearance searches for confusingly similar marks in the US, EU, PRC, Japan, and South Korea and have not identified any third-party marks that we consider to present a significant risk of confusion with Halcyon's principal marks.
D. Adequacy Assessment
We assess Halcyon's trademark portfolio as generally adequate for a US-listed public company operating in the semiconductor industry. The portfolio provides comprehensive protection for the Company's corporate name, logo, and principal product line brands across all key markets. We make the following supplemental recommendations:
1. We recommend that Halcyon file intent-to-use trademark applications in the United States for any new product line marks anticipated to be launched in connection with or following the IPO, to ensure priority protection in advance of commercial use.
2. We recommend that the Company formalize intra-group trademark license agreements with each subsidiary that uses Halcyon trademarks, including quality control provisions to maintain the validity and enforceability of the registrations.
3. We recommend that the Company consider extending its trademark portfolio to additional jurisdictions where it anticipates significant sales growth (e.g., India, Brazil, and certain Middle Eastern markets) in advance of market entry.
V. IP LICENSING AGREEMENTS
A. Inbound Licenses (Halcyon as Licensee)
Halcyon is a party to several material inbound patent and technology license agreements under which the Company uses intellectual property owned by third parties. We have reviewed the following material inbound licenses:
1. License Agreement with Cree Aldermere Corporation (n/k/a Glenrock Partners LLC)
Licensor: Glenrock Partners LLC (Durham, NC, USA) Technology Covered: SiC substrate and epitaxial processing technology, including certain SiC crystal growth and wafer processing patents Scope: Non-exclusive, worldwide license for the manufacture and sale of SiC power semiconductor devices Term: Ten-year term commencing January 1, 2020; auto-renewal for successive three-year periods unless terminated with 12 months' prior written notice Royalty: Running royalty of [*]% of net sales of licensed products, with minimum annual royalty of $[]; paid quarterly Change-of-Control Provisions: The agreement defines "change of control" as the acquisition by a single entity (or group of related entities) of more than 50% of the outstanding voting securities of Halcyon Semiconductor AG, or the sale of all or substantially all of the Company's assets. The proposed IPO, which involves the issuance of new ordinary shares and establishment of an ADR program but does not result in any single entity acquiring more than 50% of the voting securities, does not constitute a "change of control" under this agreement. Accordingly, no consent or notification to Aldermere Corporation is required in connection with the IPO. Assignment Restrictions: The agreement prohibits assignment without the prior written consent of Aldermere Corporation, except in connection with a merger or acquisition of all or substantially all of the assets of the licensee. The establishment of the ADR program and listing on Nasdaq does not constitute an "assignment" under this provision. Termination Provisions: Termination for material breach (with 60-day cure period); termination upon insolvency or bankruptcy of either party; no termination for convenience by licensor during the initial term. Assessment:* This is the most significant inbound license in the Halcyon portfolio. While Halcyon has developed substantial independent SiC technology, certain aspects of the Company's SiC substrate processing rely on techniques covered by the Aldermere Corporation licensed patents. Dr. Helder has confirmed that Halcyon has developed design-around alternatives for the most critical licensed techniques, although implementing these alternatives on a production scale would require approximately 12–18 months and capital investment of approximately €40–60 million. We recommend that this license dependency be disclosed in the Form F-1 risk factors.
2. License Agreement with Adriatic Holdings
Licensor: Adriatic Holdings (Kyoto, Japan) Technology Covered: SiC trench MOSFET gate oxide formation techniques and certain SiC module packaging patents Scope: Non-exclusive license for Germany, the EU, the US, the PRC, Japan, and South Korea Term: Eight-year term commencing April 1, 2021; renewable by mutual agreement Royalty: Lump-sum license fee of ¥[*] paid at execution; no running royalties Change-of-Control Provisions: The agreement contains a change-of-control notification provision (but not a consent or termination right) requiring Halcyon to provide 30 days' prior written notice to Rohm upon the occurrence of a change of control. The definition of "change of control" is substantially similar to that in the Aldermere Corporation agreement, and the IPO does not trigger this provision. Assessment: This license provides supplemental patent clearance for certain aspects of Halcyon's SiC trench MOSFET manufacturing process. The lump-sum fee structure is favorable, as it eliminates ongoing royalty obligations. The licensed technology represents a relatively narrow aspect of Halcyon's overall manufacturing process, and the Company has confirmed that it possesses independent proprietary alternatives.
3. Technology License Agreement with Fraunhofer Institute for Applied Solid State Physics (IAF)
Licensor: Calderon Group, acting through the Fraunhofer Institute for Applied Solid State Physics IAF (Freiburg, Germany) Technology Covered: GaN epitaxial growth techniques on SiC substrates, including certain buffer layer engineering methods Scope: Exclusive license for power electronics applications; worldwide territory Term: Fifteen-year term commencing July 1, 2018; non-renewable Royalty: Running royalty of [*]% of net sales of GaN-on-SiC products incorporating the licensed technology; minimum annual royalty of €[] Change-of-Control Provisions: None. The agreement do