Final verdict on SiC ring patents threatens TCK’s dominance

A Supreme Court ruling made on Thursday on the validity of patents related to silicon carbide (SiC) rings owned by Tokai Carbon Korea (TCK) is expected to disrupt the market in South Korea.

The ruling maintained the verdict of the appeals court in October last year and validated a patent related to the manufacturing of the rings but invalidated another related to properties of the ring.

TCK claimed that as its patent on manufacture and device were validated, its rival DS Techno will find it difficult to work workaround them.

Meanwhile, rival DS Techno alleged that patents related to properties were the core and those have been invalidated, opening the doors for the company to expand in the SiC ring sector.

SiC rings are commodities used to hold the wafer in place during chip production.

SiC is more durable than silicon and quartz which were also used to produce these rings.

SiC rings are mostly used within etching chambers and are widely used in the production 3D NAND flashes that go through many etching processes.

TCK is a subsidiary of Japan’s Tokai Carbon and had control over 80% of the market share in South Korea, thanks much to its patents that prevented rivals from coming into the market.

DS Techno began manufacturing its own SiC rings however and TCK filed two patent infringement lawsuits against the company in November 2019.

The latest ruling by the Supreme Court invalidated Patent 1866869 related to properties that were one of the subjects of these lawsuits.

But TCK validated its Patent 1914289 related to SiC ring with layers with different transmittance levels and manufacture and device; the transmittance part of the patent was invalidated that but the manufacturing part was validated.

TCK claims that the manufacturing part is crucial. The company said SiC ring in gas form is sprayed on the ring sequentially with multiple nozzles.

It said DS Techno will likely use multiple nozzles to form the layers on SiC ring, and this violates its patents.

However, DS Techno refutes this and said even if it swaps nozzles the details of how they proceed to manufacture SiC ring are different.

Meanwhile, besides the pair, Hana Materials and KNJ are also showing interest in manufacturing SiC rings.