| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device having sufficient element-to-element voltage resistance while forming a uniform CVD oxide film within a trench by forming uneven concave and convex surfaces on the bottom surface of the trench through an etching process and also provide a method for manufacturing the semiconductor device. SOLUTION: In a semiconductor device having the trench 11 within a semiconductor substrate 10, roughness 11b shaped by uneven concave and convex surfaces in almost equal height is formed through at the bottom surface 11a of the trench 11 a dry etching process. Actually, the trench 11 is formed on a semiconductor substrate 10 by adjusting at least a parameter of the etching conditions. With such an etching process, roughness 11b having a tapering angle of α that is almost perpendicular is formed on the bottom surface 11a. Moreover, the number of faults generated during the formation of the trench 11 can be reduced. In addition, a trench structure provided with roughness 11b improves the voltage resistance of well. COPYRIGHT: (C)2009,JPO&INPIT
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