Patent ID: 6429501
Filing Date: 2002-08-06
Classification: H01L

Abstract:
A semiconductor device comprising:a semiconductor substrate of a first conductivity type; a first diffusion layer of a second conductivity type formed in a central surface portion of the substrate, the first diffusion layer serving as an anode; a second diffusion layer of the second conductivity type, which is formed in a surface portion of the substrate, has a lower impurity concentration than the first diffusion layer, and is located outside and in contact with the first diffusion layer; a third diffusion layer of the first conductivity type, which is formed in a surface portion of the substrate, is located outside the first diffusion layer, and is separated from the first diffusion layer by a predetermined distance; a recess formed in that surface portion of the substrate between the first and third diffusion layers, which includes a surface portion of the second diffusion layer; a semiconductive film formed in the recess; and a fourth diffusion layer formed in a reverse surface of the substrate and having a higher impurity concentration than the substrate, the fourth diffusion layer serving as a cathode.