Defending Eugene Tech in semiconductor ALD equipment patent dispute against Japanese company

Lee & Ko’s IP & Technology Practice Group, representing Eugene Tech, successfully invalidated the patents of Japan’s Kokusai Electric (“Kokusai”) in a patent dispute concerning atomic layer deposition (“ALD”) equipment used in semiconductor processing.

In February 2024, Kokusai filed four patent infringement lawsuits against Eugene Tech in the Seoul Central District Court. The technology at issue related to semiconductor process equipment, and Kokusai brought the infringement suits based on patents spanning various fields, including process operation methods and equipment configurations.

Lee & Ko’s IP & Technology Group responded to the infringement suits by asserting non-infringement while safeguarding Eugene Tech’s trade secrets, and at the same time sought to invalidate Kokusai’s patents by filing invalidation actions against all four patents.

With respect to the patent relating to nozzle arrangement among Kokusai’s patents, in December 2024, the Intellectual Property Trial and Appeal Board (“IPTAB”) held that all of the claims Kokusai had asserted for infringement were invalid. Although Kokusai filed a suit to revoke this decision, the IP High Court rendered a judgment in May 2026 upholding the IPTAB’s determination. In addition, with respect to a patent relating to semiconductor processing, although the IPTAB dismissed Eugene Tech’s petition for an invalidation action, in the correction action that Kokusai filed to amend the scope of its patent claims, it was determined that the invention described in the corrected claims lacked inventive step compared to the prior art, thereby succeeding in effectively neutralizing Kokusai’s patent.

Accordingly, Eugene Tech has effectively neutralized two of Kokusai’s four patents, and by mounting effective invalidity arguments against the remaining two patents as well, it is successfully responding to Kokusai’s infringement claims. As a result, Eugene Tech is now positioned to continue expanding its competitiveness and influence in the market as a promising equipment company in the rapidly advancing semiconductor industry.