| 摘要 |
PURPOSE:To improve breakdown voltage by a method wherein a substance of a composition ratio between a Si3N4 layer and a Si base body is interposed between them, stress to the Si base body side is reduced, a bird beak is made small, and the leakage currents of a junction section is minimized. CONSTITUTION:A pad layer 12 of an intermediate substance of Si and Si3N4 is applied onto the P type Si base body 11 through a CVD method, the Si3N4 film 13 is superposed and patterned, and a thick SiO2 film 14 is formed through oxidation. Since the pad 12 is of a composition between Si and Si3N4 and has comparatively compact structure, O2 does not reach to the Si base body through the pad 12, and the bird beak is made small. Since stress applied to the base body is reduced and the generation of the crystal defect of the base body is inhibited, leakage currents are little when the pad is removed and an N<+> diffusion layer is formed, and breakdown voltage is not also lowered. |
