| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that the body region of a MOSFET is formed through oblique ion implantation from one direction, and the body region after diffusion is not homogeneously formed, and an avalanche resistance is weak, and the variations increase, because a low concentration region (laterally asymmetric in the sectional structure) is formed partially. SOLUTION: The impurity concentration distribution in the sectional structure, is formed to be bilaterally symmetrical by implanting ions from a plurality of directions, in the ion implantation of the body region. In the body region, the peripheral portion is a first body region in a low concentration, and the center portion is a second body region in a high concentration. The impurity concentration distribution is formed to be bilaterally symmetrical. Moreover, a peak concentration position of the body region is made deeper than the bottom of the source region, by increasing an implantation energy in comparison with a conventional one. Thus, the avalanche resistance is improved, and the variation is suppressed. COPYRIGHT: (C)2010,JPO&INPIT
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