Signing of a Letter of Intent for Joint Research on Diamond Device Materials with Honda R&D Co., Ltd.

1. Introduction Development of various diamond devices is accelerating. The realization of power devices for use in electric vehicles and other applications is highly anticipated, as it will solve existing device challenges and enable widespread adoption. Honda R&D Co., Ltd. (hereinafter "Honda R&D") has already been advancing this development. In March 2025, they jointly published a paper with the National Institute of Advanced Industrial Science and Technology (AIST) demonstrating the potential of high-current devices, and in February 2026, they established the "Honda R&D-AIST Diamond x Electronics Collaboration Research Laboratory" as an open innovation hub for diamond semiconductors.

Our company has consistently supported this development from the side, by commercializing various diamond substrates and wafers for the development of diamond devices. In February 2025, we commercialized the world's largest 30x30mm single crystal, and in April of the same year, we began selling 1-inch wafers (25mm diameter). As various research institutions pursue their efforts, the structures of diamond devices under development have diversified, leading us to commercialize low-resistance substrates and substrates with various epitaxial layers. As a result, our company has commercialized the largest number of products globally for diamond device development.

In light of these circumstances, our company and Honda R&D have agreed to commence discussions toward conducting joint research, with a view to accelerating the development for practical application of diamond power devices.

2. Key Points of Basic Agreement Diamond devices, when applied to power devices used in future electric vehicles and other applications, are expected to improve fuel efficiency through enhanced basic performance, and also possess the characteristic of not having resource issues, as pointed out with gallium nitride. However, numerous challenges currently exist in using diamond as a semiconductor device. Furthermore, using devices made of new semiconductor materials in automobiles requires a long development period due to long-term durability tests, etc. In the production of semiconductor devices for automobiles, it is desirable to use established device fabrication processes. Therefore, without prior development in diamond materials, smooth device development itself may not be possible.

The letter of intent signed this time aims to discuss the conclusion of a joint research agreement, with the primary themes being the enlargement and quality improvement of diamond wafers, so that considerations for mass production can proceed in future device development.

Solving these challenges will enable mass production of devices using existing semiconductor processes and the production of diamond devices. By advancing joint research, the future vision for mass production will become clear, and the roadmap for subsequent device development will be defined. As a result, specific development plans for the practical application of power devices in automobiles can be formulated, making it possible to shift development to a new phase.

3. Next Steps Based on This Agreement According to the terms of this agreement, we aim to sign a formal joint research agreement with Honda R&D by the end of August 2026. After the joint research agreement is signed, we will commence this development using our existing facilities, and sequentially plan to introduce new necessary equipment and construct facilities for experiments.

4. Our Company's Future Plan Our company's roadmap for diamond wafer development, announced on November 28, 2024, outlined a plan to expand wafer sizes from 2-inch wafers to 4-inch wafers. The development of 2-inch wafers is currently progressing diligently, and our policy to realize these products remains unchanged. Various products that can be commercialized through this joint research are also planned for widespread sale with the aim of popularizing diamond devices.

As a supplier of various diamonds necessary for the development of diamond devices, our company will continue to lead global development and promote standardization of each product, thereby playing a role in the early practical application of diamond devices.

For inquiries regarding this matter: EDP Co., Ltd. Sales Department 4-6-3 Kamishinada, Toyonaka City, Osaka 560-0085, Japan (Email) edp.info@d-edp.jp Website: <a target="_blank" rel="nofollow ugc noopener" class="p...