US 7,605,040 B2 · Method of forming high breakdown voltage low on-resistance lateral DMOS transistor

Abstract

A method of forming a metal oxide semiconductor (MOS) transistor includes the following steps. A substrate of a first conductivity is provided. A first buried layer of a second conductivity type is formed over the substrate. A second buried layer of the first conductivity type is formed in the first buried layer. An epitaxial layer of the second conductivity type is formed over the substrate. A drift region of a second conductivity type is formed in the epitaxial layer. A gate layer is formed over the drift region. A body region of the first conductivity type is formed in the drift region such that the gate overlaps a surface portion of the body region. A source region of the second conductivity is formed in the body region. A drain region of the second conductivity type is formed in the drift region. The drain region is laterally spaced from the body region. The first and second buried layers laterally extend from under the body region to under the drain region. The surface portion of the body region extends between the source region and the drift region to form a channel region of the transistor.

Claims10

Dependent claims

A method of forming a metal oxide semiconductor (MOS) transistor, comprising:

providing a substrate of a first conductivity type;
forming a first buried layer of a second conductivity type in the substrate;
forming a second buried layer of the first conductivity type in the first buried layer;
forming an epitaxial layer of the second conductivity type over the substrate;
forming a drift region of a second conductivity type in the epitaxial layer;
forming a gate layer over the drift region;
forming a body region of the first conductivity type in the drift region such that the gate overlaps a surface portion of the body region;
forming a source region of the second conductivity in the body region;
and
forming a drain region of the second conductivity type in the drift region, the drain region being laterally spaced from the body region;
wherein the first and second buried layers laterally extend from under the body region to under the drain region, and the surface portion of the body region extends between the source region and the drift region to form a channel region of the transistor.

8 more elements

Dependencies are inferred from the claim text.

Method of forming high breakdown voltage low on-resistance lateral DMOS transistor

Life of this patent

Method of forming high breakdown voltage low on-resistance lateral DMOS transistor

Life of this patent

Abstract

Claims10