| 摘要 |
<p>PURPOSE:To acquire stable characteristics without being affected by an oxide film, an Al line, etc., on a silicon layer surface by producing breakdown of a zener diode at a P-N junction of a deep part of a silicon layer. CONSTITUTION:A mask window C of an N<+>-diffusion is made larger than a mask window A of P-diffusion to enable diffusion of an N<+>-diffusion layer 2a whose peripheral part is a region of low impurity concentration of a P- isolation diffusion region 1. In a P-N junction near a silicon layer surface, a concentration of the P-diffusion layer 1 is low, and breakdown occurs mainly at a P-N junction section 3a of a deep section of a silicon layer. Therefore, stable characteristics ca be acquired without being affected by an oxide film on a silicon layer surface, an Al line, etc.</p> |
