US 5,970,329 A · Method of forming power semiconductor devices having insulated gate electrodes

Abstract

Methods of forming power semiconductor devices include the steps of forming an insulated gate electrode on a face of semiconductor substrate containing a body region of first conductivity type (e.g., P-type) therein extending to the face. Using the gate electrode as a mask, a step is then performed to oxidize the body region and substrate at the face to form a first oxide layer. Source and drain region dopants are then implanted through the first oxide layer and into the body region and substrate to define recessed source and drain regions of second conductivity type therein, respectively. The step of implanting source and drain region dopants may be preceded by the step of etching the first oxide layer using an etching mask which covers the gate electrode. The step of oxidizing the body region and substrate may also be preceded by the step of forming nitride spacers on sidewalls of the gate electrode and then also using the nitride spacers as a mask during the oxidation step. These nitride spacers are then removed prior to performing the step of implanting the source and drain region dopants.

Claims10

Dependent claims

A method of forming a transistor, comprising the steps of:

forming an insulated gate electrode on a face of a semiconductor substrate of first or second conductivity type;
implanting dopants of second conductivity type into the semiconductor substrate to define a body region of second conductivity type therein, using the insulated gate electrode as an implant mask;
forming first spacers on sidewalls of the insulated gate electrode;
thermally oxidizing the body region using the first spacers as an oxidation mask;
removing the first spacers;
incorporating first dopants of first conductivity type into the insulated gate electrode, using a thermally oxidized portion of the body region as a dopant mask which inhibits transfer of first dopants into the body region;
then
etching the thermally oxidized portion of the body region to reduce the thickness thereof;
then
implanting second dopants of first conductivity type through the thermally oxidized portion of the body region and into the body region to define a source region therein;
and then
etching the thermally oxidized portion of the body region to expose the source region.

9 more elements

Dependencies are inferred from the claim text.

Method of forming power semiconductor devices having insulated gate electrodes

Life of this patent

Method of forming power semiconductor devices having insulated gate electrodes

Life of this patent

Abstract

Claims10