Method of manufacturing bipolar transistor

Claim 1

A method of manufacturing a bipolar transistor, comprising the steps of: a) forming an anti-oxidation film on a semiconductor wafer having a collector region of a first conductivity type, and stacking an insulating film for step forming on said anti-oxidation film; b) patterning stacked films consisting of said anti-oxidation film and said insulating film for step forming to form a stacked film pattern covering an internal base region prospective portion; c) depositing a first mask material film on the entire surface; d) depositing a conductive material on the surface to cover said first mask material film, thereby forming a first conductive film used as a part of a base electrode; e) burying a second mask material film pattern in a recess on the surface of said first conductive film; f) selectively etching said first conductive film using said second mask material film pattern as an etching mask t expose said first mask material film on said stacked film pattern; g) completely, selectively etching said first conductive film by anistropic etching using said exposed first mask material film and said second mask material film patterns as etching masks, and exposing the surface of said collector region, thereby forming a first opening for forming an external base region between said two mask material film patterns; h) removing said second mask material film pattern; i) burying a second conductive film doped with an impurity of the first conductivity type serving as a base electrode in said first opening; j) removing first mask material film left on the side wall of said stacked film pattern and said insulating film for step forming which constitutes said stacked film pattern thereby forming a second opening for forming an internal base region; k) performing thermal oxidation using said anti-oxidation film left in step j) to form a thermal oxide film on a surface of said second conductive film, and diffusing the impurity contained in said second conductive film into said collector region, thereby forming said external base region of a second conductivity type; l) doping an impurity of the second conductivity type into said wafer through said second opening, thereby forming an emitter region of the second conductivity type; m) exposing the wafer surface through said second opening, and depositing a third conductive film serving as a part of an emitter electrode; and n) diffusing an impurity of the first conductivity type from said third conductive film in said wafer to form an emitter region of the first conductivity type.

Claim 2

A method of manufacturing a bipolar transistor, comprising the steps of: a) forming an anti-oxidation film on a semiconductor wafer having a collector region of a first conductivity type, and stacking an insulating film for step forming on said anti-oxidation film; b) patterning stacked films consisting of said anti-oxidation film and said insulating film for step forming to form a stacked film pattern covering an internal base region prospective portion; c) depositing a first mask material film on the entire surface; d) depositing a conductive material on the surface to cover said first mask material film, thereby forming a first conductive film used as a part of a base electrode; e) burying a second mask material film pattern in a recess on the surface of said first conductive film; f) selectively etching said first conductive film using said second mask material film pattern as an etching mask t expose said first mask material film on said stacked film pattern; g) completely, selectively etching said first conductive film by anistropic etching using said exposed first mask material film and said second mask material film patterns as etching masks, and exposing the surface of said collector region, thereby forming a first opening for forming an external base region between said two mask material film patterns; h) removing said second mask material film pattern; i) burying a second conductive film doped with an impurity of the first conductivity type serving as a base electrode in said first opening; j) removing first mask material film left on the side wall of said stacked film pattern and said insulating film for step forming which constitutes said stacked film pattern thereby forming a second opening for forming an internal base region; k) performing thermal oxidation using said anti-oxidation film left in step j) to form a thermal oxide film on a surface of said second conductive film, and diffusing the impurity contained in said second conductive film into said collector region, thereby forming said external base region of a second conductivity type; l) doping an impurity of the second conductivity type into said wafer through said second opening, thereby forming an emitter region of the second conductivity type; m) exposing the wafer surface through said second opening, and depositing a third conductive film serving as a part of an emitter electrode; and n) diffusing an impurity of the first conductivity type from said third conductive film in said wafer to form an emitter region of the first conductivity type.

Claim 7

A method of manufacturing a bipolar transistor, comprising the steps of: a) forming an anti-oxidation film on a semiconductor wafer having a collector region of a first conductivity type, and stacking an insulating film for step forming on said anti-oxidation film; b) patterning stacked films consisting of said anti-oxidation film and said insulating film for step forming to form a stacked film pattern covering an internal base region prospective portion; c) depositing a first mask material film on the entire surface; d) depositing a conductive material on the surface to cover said first mask material film, thereby forming a first conductive film used as a part of a base electrode; e) burying a second mask material film pattern in a recess on the surface of said first conductive film; f) selectively etching said first conductive film using said second mask material film pattern as an etching mask t expose said first mask material film on said stacked film pattern; g) completely, selectively etching said first conductive film by anistropic etching using said exposed first mask material film and said second mask material film patterns as etching masks, and exposing the surface of said collector region, thereby forming a first opening for forming an external base region between said two mask material film patterns; h) removing said second mask material film pattern; i) burying a second conductive film doped with an impurity of the first conductivity type serving as a base electrode in said first opening; j) removing said insulating film for step forming which constitutes said stacked film pattern thereby forming a second opening for forming an internal base region, said first mask material film being remained on the side wall of said stacked film pattern; k) performing thermal oxidation using said anti-oxidation film left in step j) to form a thermal oxide film on a surface of said second conductive film, and diffusing the impurity contained in said second conductive film into said collector region, thereby forming said external base region of a second conductivity type; l) doping an impurity of the second conductivity type into said wafer through said second opening, thereby forming an emitter region of the second conductivity type; m) exposing the wafer surface through said second opening, and depositing a third conductive film serving as a part of an emitter electrode; and n) diffusing an impurity of the first conductivity type from said third conductive film in said wafer to form an emitter region of the first conductivity type.

Claim 8

A method of manufacturing a bipolar transistor, comprising the steps of: a) forming an anti-oxidation film on a semiconductor wafer having a collector region of a first conductivity type, and stacking an insulating film for step forming on said anti-oxidation film; b) patterning stacked films consisting of said anti-oxidation film and said insulating film for step forming to form a stacked film pattern covering an internal base region prospective portion; c) depositing a first mask material film on the entire surface; d) depositing a conductive material on the surface to cover said first mask material film, thereby forming a first conductive film used as a part of a base electrode; e) burying a second mask material film pattern in a recess on the surface of said first conductive film; f) selectively etching said first conductive film using said second mask material film pattern as an etching mask t expose said first mask material film on said stacked film pattern; g) completely, selectively etching said first conductive film by anistropic etching using said exposed first mask material film and said second mask material film patterns as etching masks, and exposing the surface of said collector region, thereby forming a first opening for forming an external base region between said two mask material film patterns; h) removing said second mask material film pattern; i) burying a second conductive film doped with an impurity of the first conductivity type serving as a base electrode in said first opening; j) removing said insulating film for step forming which constitutes said stacked film pattern thereby forming a second opening for forming an internal base region, said first mask material film being remained on the side wall of said stacked film pattern; k) performing thermal oxidation using said anti-oxidation film left in step j) to form a thermal oxide film on a surface of said second conductive film, and diffusing the impurity contained in said second conductive film into said collector region, thereby forming said external base region of a second conductivity type; l) doping an impurity of the second conductivity type into said wafer through said second opening, thereby forming an emitter region of the second conductivity type; m) exposing the wafer surface through said second opening, and depositing a third conductive film serving as a part of an emitter electrode; and n) diffusing an impurity of the first conductivity type from said third conductive film in said wafer to form an emitter region of the first conductivity type.