| 摘要 |
PURPOSE:To minimize the dynamic resistance and the noise at the rise time, by establishing the resistivity of the single crystal substrate for the constant voltage semiconductor device at 0.005-0.006OMEGAcm. CONSTITUTION:On the P type Si substrate 1 whose resistivity is below 0.001OMEGAcm, the N type layer 2 whose resistivity and thickness is 0.005-0.006OMEGAcm and 6-7mum respectively is epitaxially grown. On the layer 2 the SiO2 film 3 is formed by heat treatment at high temperature, and after removing some part the shallow P type region 4 is diffusion-formed in the exposed layer 2. Here the Al electrode 5 is mounted. Because the sensitivity of the layer 2 is established at 0.005-0.006OMEGAcm instead of usual 0.0035-0.0045OMEGAcm and the depth of the diffusion region 4 is made shallower, the breakdown always takes the form of the avalanche breakdown, and the dynamic resistance for the low intensity current becomes smaller, resulting in the lesser noises. |
