| 摘要 |
PURPOSE:To obtain a Zener diode having excellent noise characteristics even at small operating currents by surrounding the other conduction type third region by the other conduction type second region having impurity concentration lower than the third region in high impurity concentration, where avalanche breakdown is generated, and positioning the corner section of a diffusion window in the second region outside one conduction type first region. CONSTITUTION:A P type impurity diffusion region (a first region) 2 is formed to an N type epitaxial layer 1. A region (a second region) 4, which has a recessed plane shape, at least recessed section thereof is brought into contact with the P type region 2 and into which an N type impurity in concentration higher than the P type region 2 is diffused, is shaped. An N type impurity diffusion region (a third region) 3 in concentration higher than the region 4 is formed so as to coat the plane-shaped bottom section of a recessed section in the region 4. Cathode and anode electrodes are each lead out of windows 40, 20 for leading out electrodes. In a Zener diode having the structure, avalanche breakdown is generated on a B-B' line surrounded by the recessed section C-D-E-F in the diffusion region 4. |
