| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device having high-breakdown voltage and high quality transistor characteristics by stabilizing a trench shape and microfabricating the trench. SOLUTION: The method for manufacturing the semiconductor device includes: a step of forming a silicon oxide film 20 on a silicon substrate 10; a step of etching the silicon oxide film 20 to form an opening 20a on part of the silicon oxide film 20; a step of isotropically etching the surface of the silicon substrate 10 from the opening 20a to cut into part of the silicon substrate 10 underneath the silicon oxide film 20 and further epitaxially etching the silicon substrate 10 to form a first groove 25 having a taper surface; a step of forming a sidewall film 35 that covers part of the taper surface of the first groove 25; a step of further etching the surface of the silicon substrate 10 from the opening 20a in the direction of thickness of the silicon substrate 10 to form a second groove 30; and a step of eliminating the silicon oxide film 20 and the side wallfilm 35 to form a trench 40. COPYRIGHT: (C)2009,JPO&INPIT
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