| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device which reduces active area width, a round-shaped pattern roughness and fineness and a dimensional difference within a wafer surface after trench etching. SOLUTION: A silicon oxide film 102, a silicon nitride film 103 and a resist pattern 104 are formed on a silicon substrate 101. The silicon nitride film 103 is etched excepting for a part in the direction of a film thickness. Then, while forming first etching prevention film 107 on the side wall of the silicon nitride film 103, a part of the remaining silicon nitride film 103 is etched to form a shape where the lower part of the silicon nitride film 103 projects. The exposed silicon oxide film 102 is etched. Then, while forming second etching prevention film 117 on the side wall of the silicon nitride film 103, the surface of the exposed silicon substrate 101 is etched to form a trench upper shoulder part to be round. COPYRIGHT: (C)2007,JPO&INPIT
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