SEMICONDUCTOR DEVICE

摘要

A protective diode is provided above a first guard ring region which surrounds an active region, with a field oxide film interposed there between. The protective diode may include a series pn zener diode in which a p+ layer and an n− layer are adjacent to each other. In a semiconductor device having the first guard ring region provided below the protective diode, cracks in the surface protective film may be prevented by providing a surface protective film that may be a polyimide film. The first guard ring region is provided below the protective diode and is connected to a second guard ring region that is provided in a portion other than the portion provided below the protective diode through a third guard ring region which is an intermediate region (R). Thus, when a surge voltage is applied, concentration of electric field on the outermost guard ring may be reduced.

主权项

1. A semiconductor device, comprising:
a semiconductor substrate of a first conductivity type; a semiconductor element that is provided on the semiconductor substrate and that includes an active region in which a main current flows and a termination structure region which surrounds the active region; a protective diode that is provided above the termination structure region, with an insulating film interposed there between, and that includes a plurality of diodes which are formed by alternately arranging first-conductivity-type semiconductor layers and second-conductivity-type semiconductor layers so as to be adjacent to each other in a direction from the active region to the outside, one end of the protective diode being electrically connected to a high-potential electrode which is provided on an outer circumferential side of the semiconductor element and is disposed outside an outer circumferential end of the outermost diffusion layer, and another other end of the protective diode being electrically connected to a gate wire of the semiconductor element which is provided on the active region side; at least one diffusion layer of a second conductivity type that is selectively provided in a surface layer of a surface of the semiconductor substrate, which comes into contact with the insulating film, so as to surround the active region in the termination structure region; and a surface protective film that covers the termination structure region, wherein the termination structure region is divided into a first section in which the protective diode is arranged, a second section which has a width that is smaller than that of the first section, and a third section which has a width that increases toward the second section to the first section and connects the first section and the second section, and wherein the diffusion layer has a ring shape in a plan view which includes a first portion that is arranged in the first section and faces the protective diode in a depth direction, a second portion that is arranged in the second section, that is disposed closer to the outer circumference of the semiconductor substrate than the first portion, and that has a surface area that is greater than that of the first portion, and a third portion that is arranged in the third section.