Methods of forming bipolar junction transistors

Claim 1

A method of forming a bipolar junction transistor, comprising the steps of: forming a first insulating layer on a face of a semiconductor substrate containing a region of a first conductivity type therein extending to the face; forming an electrically conductive layer on the first insulating layer, opposite the face; patterning the electrically conductive layer to define an extrinsic base region contact layer having an exposed sidewall, on a first portion of the first insulating layer; patterning the first insulating layer to define a second portion thereof and a first opening therein which exposes the region of first conductivity type at the face; forming an electrically conductive sidewall spacer of a second conductivity type on the exposed sidewall of the extrinsic base region contact layer and on the exposed region of first conductivity type at the first opening in the patterned first insulating layer; forming a second insulating layer on the extrinsic base region contact layer and sidewall spacer of second conductivity type while simultaneously diffusing dopants of second conductivity type from the sidewall spacer into the exposed region of first conductivity type to define an extrinsic base region of second conductivity type therein; forming an intrinsic base region of second conductivity type in the region of first conductivity type to define a base-collector P-N junction; patterning the second portion of the first insulating layer to define a second opening therein which exposes a portion of the intrinsic base region at the face; and forming an emitter region of first conductivity type in the exposed portion of the intrinsic base region to define an emitter-base P-N junction.

Claim 2

A method of forming a bipolar junction transistor, comprising the steps of: forming a first insulating layer on a face of a semiconductor substrate containing a region of a first conductivity type therein extending to the face; forming an electrically conductive layer on the first insulating layer, opposite the face; patterning the electrically conductive layer to define an extrinsic base region contact layer having an exposed sidewall, on a first portion of the first insulating layer; patterning the first insulating layer to define a second portion thereof and a first opening therein which exposes the region of first conductivity type at the face; forming an electrically conductive sidewall spacer of a second conductivity type on the exposed sidewall of the extrinsic base region contact layer and on the exposed region of first conductivity type at the first opening in the patterned first insulating layer; forming a second insulating layer on the extrinsic base region contact layer and sidewall spacer of second conductivity type while simultaneously diffusing dopants of second conductivity type from the sidewall spacer into the exposed region of first conductivity type to define an extrinsic base region of second conductivity type therein; forming an intrinsic base region of second conductivity type in the region of first conductivity type to define a base-collector P-N junction; patterning the second portion of the first insulating layer to define a second opening therein which exposes a portion of the intrinsic base region at the face; and forming an emitter region of first conductivity type in the exposed portion of the intrinsic base region to define an emitter-base P-N junction.

Claim 20

A method of forming a bipolar junction transistor, comprising the steps of: forming a first insulating layer on a face of a semiconductor substrate containing a collector region of a first conductivity type therein, said first insulating layer having an opening therein exposing the collector region at the face; forming an extrinsic base region contact layer of a second conductivity type on a first portion of the first insulating layer and in the opening therein; forming an extrinsic base region of second conductivity type in the collector region, at the opening in the first insulating layer; forming a second insulating layer on the extrinsic base region contact layer and on a second portion of the first insulating layer; forming an intrinsic base region of second conductivity type in the collector region by implanting dopants of second conductivity type through the second portion of the first insulating layer and into the collector region; and forming an emitter region of first conductivity type in the intrinsic base region.

Claim 21

A method of forming a bipolar junction transistor, comprising the steps of: forming a first insulating layer on a face of a semiconductor substrate containing a collector region of a first conductivity type therein, said first insulating layer having an opening therein exposing the collector region at the face; forming an extrinsic base region contact layer of a second conductivity type on a first portion of the first insulating layer and in the opening therein; forming an extrinsic base region of second conductivity type in the collector region, at the opening in the first insulating layer; forming a second insulating layer on the extrinsic base region contact layer and on a second portion of the first insulating layer; forming an intrinsic base region of second conductivity type in the collector region by implanting dopants of second conductivity type through the second portion of the first insulating layer and into the collector region; and forming an emitter region of first conductivity type in the intrinsic base region.

Claim 27

A method of forming a bipolar junction transistor, comprising the steps of: forming a first insulating layer on a face of a semiconductor substrate containing a collector region of a first conductivity type therein extending to the face, said first insulating layer having an opening therein exposing the collector region at the face; forming an extrinsic base region contact layer of a second conductivity type on a first portion of the first insulating layer and in the opening therein; forming an extrinsic base region of second conductivity type in the collector region, at the opening in the first insulating layer; forming a second insulating layer on the extrinsic base region contact layer and on a second portion of the first insulating layer; forming an intrinsic base region of second conductivity type in the collector region by implanting dopants of second conductivity type through the second portion of the first insulating layer and into the collector region; and forming an emitter region of first conductivity type in the intrinsic base region; wherein said extrinsic base region contact layer forming step comprises the steps of forming a layer of polycrystalline silicon on the first insulating layer and then dry etching the polycrystalline silicon layer using the second portion of the first insulating layer as an etching mask to protect a portion of the collector region extending to the face.

Claim 28

A method of forming a bipolar junction transistor, comprising the steps of: forming a first insulating layer on a face of a semiconductor substrate containing a collector region of a first conductivity type therein extending to the face, said first insulating layer having an opening therein exposing the collector region at the face; forming an extrinsic base region contact layer of a second conductivity type on a first portion of the first insulating layer and in the opening therein; forming an extrinsic base region of second conductivity type in the collector region, at the opening in the first insulating layer; forming a second insulating layer on the extrinsic base region contact layer and on a second portion of the first insulating layer; forming an intrinsic base region of second conductivity type in the collector region by implanting dopants of second conductivity type through the second portion of the first insulating layer and into the collector region; and forming an emitter region of first conductivity type in the intrinsic base region; wherein said extrinsic base region contact layer forming step comprises the steps of forming a layer of polycrystalline silicon on the first insulating layer and then dry etching the polycrystalline silicon layer using the second portion of the first insulating layer as an etching mask to protect a portion of the collector region extending to the face.