| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique of protective element formation capable of reducing the number of processes. SOLUTION: In this semiconductor device where a semiconductor element is formed on an insulation film formed in a predetermined region on a principal surface of a semiconductor substrate, the insulation film is formed in the region with a space, and a semiconductor layer of a conductive type opposite to the principal surface of the semiconductor substrate is formed on the semiconductor substrate principal surface located in the space. Specifically, in the semiconductor device where a power MISFET is formed in a cell region defined by a field insulation film formed in the predetermined region of the semiconductor substrate principal surface, and a semiconductor element is formed on the field insulation film, the field insulation film is formed in the region with a space, and a semiconductor layer of a conductive type opposite to the principal surface of the semiconductor substrate is formed on the semiconductor substrate principal surface located in the space. According to the above means, since the need of forming a p-type layer just below the field insulation film is obviated, while preventing formation of a parasitic MISFET and degradation of the withstand voltage, the number of processes can be reduced. COPYRIGHT: (C)2009,JPO&INPIT
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