| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor substrate, with which the occurrence of a parasitic MOS or the degradation of reliability of a gate insulating film can be suppressed in a semiconductor substrate and a semiconductor device having an SOI structure, and to provide a method of manufacturing a semiconductor device, and the semiconductor device. SOLUTION: Since the film thickness of an LOCOS film 4 can be controlled, the semiconductor substrate is formed so that the height H, between the upper surface 1A of a bulk silicon wafer 1 and the upper surface of the LOCOS film 4, is adjusted to be larger than the height h between the upper surface 1A thereof and the upper surface of a silicon layer 52 having an SOI structure 5, beforehand. As a result, the quantity or the duration to etch a support body on the silicon layer, having the SOI structure, can be controlled by the height H, and variations in wet etching can be also suppressed. Thus, when the upper surface of the silicon layer 52 is exposed, the exposure of corners of the silicon layer 52 can be lessened. As a result, the occurrence of a parasitic MOS or the degradation of the reliability of a gate insulating film can be suppressed. COPYRIGHT: (C)2007,JPO&INPIT
|
