| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device having transistors of different gate breakdown voltages and drain breakdown voltages on the same semiconductor layer. SOLUTION: The method of manufacturing a semiconductor device includes a step of forming first impurity layers which become first wells 20 and 22 in a high breakdown voltage transistor forming region 100 contained in the semiconductor layer 10, a step of forming second impurity layers which become offset regions 30 and 32 in the region 100, and a step of forming the first wells 20 and 22 and offset regions 30 and 32 by diffusing the impurities contained in the first and second impurity layers by heat treating the semiconductor layer 10. The method also includes a step of forming element separating regions 110, 120, and 210 in the semiconductor layer 10 by the trench isolation method after the first wells 20 and 22 and offset regions 30 and 32 are formed, a step of forming first gate insulating layers 60 and 62 in the high breakdown voltage transistor forming region 100, and a step of forming second wells 24 and 26 in a low-voltage-driven transistor forming region 200 contained in the semiconductor layer 10. In addition, the method also includes a step of forming second gate insulating layers 64 and 66 in the region 200, and a step of forming gate electrodes 70, 72, 74, and 76 in the high breakdown voltage transistor forming region 100 and low-voltage-driven transistor forming region 200. COPYRIGHT: (C)2005,JPO&NCIPI
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