Method of manufacturing bipolar transistor

Claim 1

A method of manufacturing a bipolar transistor, comprising the steps of: (a) forming an insulating film on a semiconductor wafer having a collector region of a first conductivity type; (b) depositing a first mask material film on the insulating film, and patterning said first mask material film, thereby forming a first mask material film pattern covering an internal base region prospective portion; (c) depositing a conductive material on the surface to cover said first mask material film pattern, thereby forming a first conductive film to be used as a part of a base electrode; (d) burying a second mask material film pattern in the surface recess of said first conductive film; (e) selectively etching said first conductive film using said second mask material film pattern as an etching mask to expose said first mask material film pattern; (f) continuously, selectively etching said first conductive film using said exposed first mask material film pattern and said second mask material film pattern as etching masks, thereby forming a first opening for forming an external base region between said two mask material film patterns; (g) removing said second mask material film pattern; (h) burying a second conductive film serving as a part of a base electrode in said first opening, while doping an impurity of a second conductivity type into said wafer through said first opening to form said external base region of the second conductivity type; (i) removing said first mask material film pattern to form a second opening for forming an internal base region; (j) forming a thermal oxide film on the surface of said second conductive film; (k) doping an impurity of the second conductivity type into said wafer through said second opening to form said internal base region of the second conductivity type; and (l) doping an impurity of the first conductivity type into said wafer through said second opening to form an emitter region of the first conductivity type in said internal base region.

Claim 2

A method of manufacturing a bipolar transistor, comprising the steps of: (a) forming an insulating film on a semiconductor wafer having a collector region of a first conductivity type; (b) depositing a first mask material film on the insulating film, and patterning said first mask material film, thereby forming a first mask material film pattern covering an internal base region prospective portion; (c) depositing a conductive material on the surface to cover said first mask material film pattern, thereby forming a first conductive film to be used as a part of a base electrode; (d) burying a second mask material film pattern in the surface recess of said first conductive film; (e) selectively etching said first conductive film using said second mask material film pattern as an etching mask to expose said first mask material film pattern; (f) continuously, selectively etching said first conductive film using said exposed first mask material film pattern and said second mask material film pattern as etching masks, thereby forming a first opening for forming an external base region between said two mask material film patterns; (g) removing said second mask material film pattern; (h) burying a second conductive film serving as a part of a base electrode in said first opening, while doping an impurity of a second conductivity type into said wafer through said first opening to form said external base region of the second conductivity type; (i) removing said first mask material film pattern to form a second opening for forming an internal base region; (j) forming a thermal oxide film on the surface of said second conductive film; (k) doping an impurity of the second conductivity type into said wafer through said second opening to form said internal base region of the second conductivity type; and (l) doping an impurity of the first conductivity type into said wafer through said second opening to form an emitter region of the first conductivity type in said internal base region.

Claim 14

A method of manufacturing a bipolar transistor, comprising the steps of: (a) forming an insulating film on a semiconductor wafer having a collector region of a first conductivity type; (b) depositing a first mask material film on the insulating film, and patterning said first mask material film, thereby forming a first mask material film pattern covering an internal base region prospective portion; (c) depositing a refractory metal on the surface to cover said first mask material film pattern, thereby forming a refractory metal film to be used as a part of a base electrode; (d) burying a second mask material film pattern in the surface recess of said refractory metal film; (e) selectively etching said refractory metal film using said second mask material film pattern as an etching mask to expose said first mask material film pattern; (f) continuously, selectively etching said refractory metal film using said exposed first mask material film pattern and said second mask material film pattern as etching masks, thereby forming a first opening for forming an external base region between said two mask material film patterns; (g) removing said second mask material film pattern; (h) burying a polycrystalline silicon film doped with an impurity of a second conductivity type and serving as a part of a base electrode in said first opening; (i) removing said first mask material film pattern to form a second opening for forming an internal base region; (j) forming a thermal oxide film on the surface of said polycrystalline silicon film to diffuse the impurity contained in said polycrystalline silicon film into said collector region, thereby forming said external base region of the second conductivity type; (k) doping an impurity of the second conductivity type in said wafer through said second opening to form said internal base region of the second conductivity type; (l) depositing a third conductive film serving as a part of an emitter electrode; and (m) diffusing an impurity of the first conductivity type from said third conductive film into said wafer to form an emitter region of the first conductivity type.

Claim 15

A method of manufacturing a bipolar transistor, comprising the steps of: (a) forming an insulating film on a semiconductor wafer having a collector region of a first conductivity type; (b) depositing a first mask material film on the insulating film, and patterning said first mask material film, thereby forming a first mask material film pattern covering an internal base region prospective portion; (c) depositing a refractory metal on the surface to cover said first mask material film pattern, thereby forming a refractory metal film to be used as a part of a base electrode; (d) burying a second mask material film pattern in the surface recess of said refractory metal film; (e) selectively etching said refractory metal film using said second mask material film pattern as an etching mask to expose said first mask material film pattern; (f) continuously, selectively etching said refractory metal film using said exposed first mask material film pattern and said second mask material film pattern as etching masks, thereby forming a first opening for forming an external base region between said two mask material film patterns; (g) removing said second mask material film pattern; (h) burying a polycrystalline silicon film doped with an impurity of a second conductivity type and serving as a part of a base electrode in said first opening; (i) removing said first mask material film pattern to form a second opening for forming an internal base region; (j) forming a thermal oxide film on the surface of said polycrystalline silicon film to diffuse the impurity contained in said polycrystalline silicon film into said collector region, thereby forming said external base region of the second conductivity type; (k) doping an impurity of the second conductivity type in said wafer through said second opening to form said internal base region of the second conductivity type; (l) depositing a third conductive film serving as a part of an emitter electrode; and (m) diffusing an impurity of the first conductivity type from said third conductive film into said wafer to form an emitter region of the first conductivity type.

Claim 16

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 the 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 to expose said first mask material film on said stacked film pattern; (g) completely, selectively etching said first conductive film by anisotropic 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 to form a second opening for forming an internal base region; (k) performing thermal oxidation using said anti-oxidation film left in step (i) to form a thermal oxide film on the 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 17

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 the 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 to expose said first mask material film on said stacked film pattern; (g) completely, selectively etching said first conductive film by anisotropic 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 to form a second opening for forming an internal base region; (k) performing thermal oxidation using said anti-oxidation film left in step (i) to form a thermal oxide film on the 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.