US 2004/0063302 A1 · Semiconductor substrate with defects reduced or removed and method of manufacturing the same, and semiconductor device capable of bidirectionally retaining breakdown voltage and method of manufacturing the same

Abstract

An N−-type silicon substrate (1) has a bottom surface and an upper surface which are opposed to each other. In the bottom surface of the N−-type silicon substrate (1), a P-type impurity diffusion layer (3) of high concentration is entirely formed by diffusing a P-type impurity. In the upper surface of the N−-type silicon substrate (1), a P-type isolation region (2) is partially formed by diffusing a P-type impurity. The P-type isolation region (2) has a bottom surface reaching an upper surface of the P-type impurity diffusion layer (3). As viewed from the upper surface side of the N−-type silicon substrate (1), the P-type isolation region (2) is formed, surrounding an N− region (1a) which is part of the N−-type silicon substrate (1). The N− region (1a) surrounded by the P-type isolation region (2) is defined as an element formation region of the N−-type silicon substrate (1). Thus obtained are a semiconductor device and a method of manufacturing the same, and a semiconductor substrate and a method of manufacturing the same, which make it possible to retain bidirectional breakdown voltages and ensure high reliability.

Claims18

Dependent claims

A semiconductor substrate, comprising:

a substrate of a first conductivity type, having a first main surface and a second main surface which are opposed to each other;
an impurity diffusion layer of a second conductivity type different from said first conductivity type, being formed in said first main surface by diffusing an impurity;
and
an impurity diffusion region of said second conductivity type, being formed partially in said second main surface by diffusing an impurity, having a bottom surface reaching said impurity diffusion layer and surrounding a portion of said substrate which has said first conductivity type in a plan view,
wherein said portion surrounded by said impurity diffusion region is defined as an element formation region.

2 more elements

A method of manufacturing a semiconductor substrate, comprising the steps of:

(a) preparing a substrate of a first conductivity type, having a first main surface and a second main surface which are opposed to each other;
(b) forming an impurity diffusion layer of a second conductivity type different from said first conductivity type by diffusing a first impurity into said substrate from said first main surface;
and
(c) forming an impurity diffusion region of said second conductivity type by diffusing a second impurity into said substrate from part of said second main surface, to have a bottom surface reaching said impurity diffusion layer and surround a portion of said substrate which has said first conductivity type in a plan view,
wherein said portion surrounded by said impurity diffusion region is defined as an element formation region.

2 more elements

A method of manufacturing a semiconductor device, comprising the steps of:

(a) preparing a substrate of a first conductivity type, having a first main surface and a second main surface which are opposed to each other;
(b) forming an impurity diffusion layer of a second conductivity type different from said first conductivity type by diffusing a first impurity into said substrate from said first main surface;
and
(c) forming an impurity diffusion region of said second conductivity type by diffusing a second impurity into said substrate from part of said second main surface, to have a bottom surface reaching said impurity diffusion layer and surround a portion of said substrate which has said first conductivity type in a plan view,
wherein said portion surrounded by said impurity diffusion region is defined as an element formation region,
the method further comprising:
(d) forming a first impurity region of said second conductivity type partially in said second main surface in said element formation region;
(e) forming a second impurity region of said first conductivity type partially in said second main surface in said first impurity region;
and
(f) forming a gate electrode on said second main surface with a gate insulating film interposed therebetween above said first impurity region positioned between said second impurity region and a portion of said substrate which has said first conductivity type,
wherein said first impurity region serves as a base of a transistor,
said second impurity region serves as an emitter of said transistor, and
said impurity diffusion layer serves as a collector of said transistor.

10 more elements

Dependencies are inferred from the claim text.

Semiconductor substrate with defects reduced or removed and method of manufacturing the same, and semiconductor device capable of bidirectionally retaining breakdown voltage and method of manufacturing the same

Life of this patent

Semiconductor substrate with defects reduced or removed and method of manufacturing the same, and semiconductor device capable of bidirectionally retaining breakdown voltage and method of manufacturing the same

Life of this patent

Abstract

Claims18