| 摘要 |
In a conventional semiconductor device, there is a problem that zener diode characteristics vary due to a crystal defect on a silicon surface, and the like. In a semiconductor device of the present invention, an N type epitaxial layer 4 is formed on a P type single crystal silicon substrate 2. In the epitaxial layer 4, P type diffusion layers 5, 6, 7 and 8 as anode regions and an N type diffusion layer 9 as a cathode region are formed. A PN junction region between the P type diffusion layer 8 and the N type diffusion layer 9 forms a zener diode 1. By use of this structure, a current path is located in a deep portion of the epitaxial layer 4. Thus, it is made possible to prevent a variation in a saturation voltage of the zener diode 1 due to a crystal defect on a surface of the epitaxial layer 4, and the like.
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