| 摘要 |
PROBLEM TO BE SOLVED: To prevent deterioration of an etching form and crack of an etching mask when a silicon substrate is selectively and anisotropically wet-etched. SOLUTION: After a silicon oxide film 14 is formed on one principal surface of a silicon substrate 10 by a thermal oxidation method, a silicon nitride film 16 is formed on the film 14 by a CVD method. The lamination of the films 14 and 16 is selectively dry-etched to form a mask opening part 22, and a remaining part of the lamination is left as an etching mask 24. Using the mask 24 and an alkaline etchant such as a TMAH, the substrate 10 is selectively and anisotropically etched to form a substrate opening part 10A. By making a ratio of thickness of the mask 14/ the mask 16 is 1.25 or more (preferably 1.60 or more), deterioration of the etching form of an opening inner wall part 10a and crack of the etching mask 24 are prevented. The film 16 may be provided with a groove 16A for relaxing a film stress applied to the mask opening part 22. COPYRIGHT: (C)2004,JPO&NCIPI |
