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US 8,138,060 B2Granted
Wafer
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsToshihiko Tsukatani, Takao Maeda, Junichi Nakayama, Hirofumi Kawazoe, Masaru Konya, Noriaki Hamaya, Hajime Nakano
Life of this patent
Estimating the term…
Abstract
A wafer has a rare earth oxide layer disposed, typically sprayed, on a substrate. It is useful as a dummy wafer in a plasma etching or deposition system.
Claims8
A wafer consisting of a silicon substrate having a surface roughness RA of 0.5 to 5 μm, a silicon layer formed on the substrate as a bond coat layer and having a surface roughness Ra of 1 to 10 μm, and a sprayed coating of rare earth oxide on the silicon layer as an outermost layer.
Dependencies are inferred from the claim text.