| 摘要 |
PURPOSE:To enhance an integration by forming a parasitic channel-stopping region to come in self-alignment relationship with a well region and a field insulating film. CONSTITUTION:A protecting film 12, a masking material layer 14, a mask layer 16 are sequentially formed on a substrate 10, with the layer 16 as a mask the layer 14 is etched to form an impurity penetrating portion 15, and an impurity is then implanted through the portion 15 and the film 12 to the substrate 10. Then, the layer 16 is removed, heat-treated to form a P-well region 18, a mask material layer 20 is deposited, mask layers 22A, 22B are formed, and an impurity is implanted to the well 18. Then, with the layers 22A, 22B as masks it is etched, and portions 20A, 20B of the layer 20 and the portion 14A of the layer 14 remain. Thereafter, a field insulating film 24 and a parasitic channel stopping region 26 directly thereunder are formed by oxidizing. According to this method, the region 26 is formed in the shape self-aligned with both the well 18 and the film 24, thereby highly integrating them.
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