🟩 what is mask blanks?
mask blanks are glass substrates that are the source of semiconductor device manufacturing. a photomask is formed by applying a metal film and a photosensitive film on a glass substrate, and a photomask is formed by exposing and developing a circuit pattern. by transferring the photomask circuit manufactured in this way to a silicon wafer, a semiconductor is formed.

🟩 japanese companies have a high market share
The global market share of mask blanks is 90% for the Japanese companies HOYA and Shin-Etsu Chemical Industries, respectively, and it is an oligopoly. The development of mask blank products compatible with EUV (extreme ultraviolet light) lithography for next-generation semiconductors is also actively being conducted.
🟩 conclusion
japanese companies have a large share of mask blanks, which are raw materials for semiconductor photomasks