| 摘要 |
PURPOSE:To prevent the generation of a parasitic channel by forming a groove section by etching an element isolation region is tapered manner and implanting the ions of an impurity of the same conduction type as a substrate to the peripheral section of the groove section. CONSTITUTION:A mask material 32 is used as a mask, the ions of the impurity 33 of the same conduction type are implanted into the element isolation region of the silicon substrate 31, and the whole is thermally treated, thus controlling the profile of the impurity 33 going around from the periphery. The groove section 34 is formed through anisotropic etching at an angle theta, the ions of the impurity 35 of the same conduction type as the substrate are implanted, the mask material 32 is removed, and an oxide film 36 is buried flatly. A gate oxide film 37 and a gate electrode 38 are formed, and source-drain diffusion layers are formed. Accordingly, an inversion preventive layer having desired profiles in a corner section 40 and a side surface 39 is formed, and the generation of the parasitic channel can be prevented. |
