Bipolar transistor device and method of manufacturing the same

Claim 1

A bipolar transistor device comprising: a collector region (112, 116) of a first conductivity type formed on a semiconductor substrate; a base region (118) of a second conductivity type formed on the collector region; a mesa type emitter region (120, 122, 124) of the first conductivity type formed on the base region; a base electrode (138) formed on the base region and separated from a bottom portion of the mesa type emitter region; a resin layer (146) formed on the base electrode and covering the base region exposed between the base electrode and the bottom portion of the emitter region, and a side face of the emitter region; and an emitter electrode (136) overlapping at its end portion with the base electrode with the resin layer being interposed.

Claim 9

A method of manufacturing a bipolar transistor device, wherein a first semiconductor layer (112, 116) of a first conductivity type, a second semiconductor layer (118) of a second conductivity type and a third semiconductor layer (120, 122, 124) of the first conduc­tivity type are sequentially laminated on a semiconduc­tor substrate, and a collector electrode (134), a base electrode (138) and an emitter electrode (136) are formed on the first to third semiconductor layers, respectively, said method comprising the steps of: forming a first mask material (132) for forming an emitter region and a second mask material (140) for forming a base electrode, on the third semiconductor layer (120, 122, 124) in this order; forming a base electrode pattern on the second mask material and forming a pattern wider than the base electrode pattern on the first mask material; performing an etching until the second semiconductor layer (118) is exposed by using the first mask material as a mask, thereby to form a mesa-type emitter region (142); depositing a metal by using the second mask material as a mask, thereby to form a base electrode (138) on the exposed second semiconductor layer; removing the second mask material (140); forming a resin layer (146) over the entire surface of the resultant structure after the second mask is removed; subjecting the formed resin layer to an etching, until the first mask material (132) is exposed; removing the first mask material (132) exposed by the etching step and exposing the third semiconductor layer (124), and forming an emitter electrode (136) on the third semiconductor layer.

Claim 10

A method of manufacturing a bipolar transistor device, wherein a first semiconductor layer (112, 116) of a first conductivity type, a second semiconductor layer (118) of a second conductivity type and a third semiconductor layer (120, 122, 124) of the first conduc­tivity type are sequentially laminated on a semiconduc­tor substrate, and a collector electrode (134), a base electrode (138) and an emitter electrode (136) are formed on the first to third semiconductor layers, respectively, said method comprising the steps of: forming a first mask material (132) for forming an emitter region and a second mask material (140) for forming a base electrode, on the third semiconductor layer (120, 122, 124) in this order; forming a base electrode pattern on the second mask material and forming a pattern wider than the base electrode pattern on the first mask material; performing an etching until the second semiconductor layer (118) is exposed by using the first mask material as a mask, thereby to form a mesa-type emitter region (142); depositing a metal by using the second mask material as a mask, thereby to form a base electrode (138) on the exposed second semiconductor layer; removing the second mask material (140); forming a resin layer (146) over the entire surface of the resultant structure after the second mask is removed; subjecting the formed resin layer to an etching, until the first mask material (132) is exposed; removing the first mask material (132) exposed by the etching step and exposing the third semiconductor layer (124), and forming an emitter electrode (136) on the third semiconductor layer.

Claim 13

A method of manufacturing a bipolar transistor device, wherein a first semiconductor layer (112, 116) of a first conductivity type, a second semiconductor layer (118) of a second conductivity type and a third semiconductor layer (120, 122, 124) of the first conductivity type are sequentially laminated on a semiconductor substrate, and a collector electrode (134), a base electrode (138) and an emitter electrode (136) are formed on the first to third semiconductor layers, respectively, said method comprising the steps of: forming a first mask material (132) for forming an emitter region and a second mask material (140) for forming a base electrode, on the third semiconductor layer (120, 122, 124) in this order; forming a base electrode pattern on the second mask material and forming a pattern wider than the base electrode pattern on the first mask material; performing an etching until the second semiconduc­tor layer (118) is exposed by using the first mask material (132) as a mask, thereby to form a mesa-type emitter region (142); depositing a metal by using the second mask material (140) as a mask, thereby to form a base electrode (138) on the exposed second semiconductor layer; removing the second mask material (140); forming a third mask material after the step of removing the second mask material; forming a collector electrode forming pattern on the third mask material and etching the first mask material (132); etching the third semiconductor layer and the second semiconductor layer by using the first mask material as a mask, until the first semiconductor layer (112) is exposed; depositing a second metal with use of the third mask material as a mask to form a collector electrode (134) on the exposed first semiconductor layer; removing the third mask material; forming a resin layer (146) over the entire surface of the resultant structure after the third mask is removed; subjecting the formed resin layer to an etching, until the first mask material (132) is exposed; removing the first mask material (132) exposed by the etching step to expose the third semiconductor layer (124); and forming an emitter electrode (136) on the third semiconductor layer.

Claim 14

A method of manufacturing a bipolar transistor device, wherein a first semiconductor layer (112, 116) of a first conductivity type, a second semiconductor layer (118) of a second conductivity type and a third semiconductor layer (120, 122, 124) of the first conductivity type are sequentially laminated on a semiconductor substrate, and a collector electrode (134), a base electrode (138) and an emitter electrode (136) are formed on the first to third semiconductor layers, respectively, said method comprising the steps of: forming a first mask material (132) for forming an emitter region and a second mask material (140) for forming a base electrode, on the third semiconductor layer (120, 122, 124) in this order; forming a base electrode pattern on the second mask material and forming a pattern wider than the base electrode pattern on the first mask material; performing an etching until the second semiconduc­tor layer (118) is exposed by using the first mask material (132) as a mask, thereby to form a mesa-type emitter region (142); depositing a metal by using the second mask material (140) as a mask, thereby to form a base electrode (138) on the exposed second semiconductor layer; removing the second mask material (140); forming a third mask material after the step of removing the second mask material; forming a collector electrode forming pattern on the third mask material and etching the first mask material (132); etching the third semiconductor layer and the second semiconductor layer by using the first mask material as a mask, until the first semiconductor layer (112) is exposed; depositing a second metal with use of the third mask material as a mask to form a collector electrode (134) on the exposed first semiconductor layer; removing the third mask material; forming a resin layer (146) over the entire surface of the resultant structure after the third mask is removed; subjecting the formed resin layer to an etching, until the first mask material (132) is exposed; removing the first mask material (132) exposed by the etching step to expose the third semiconductor layer (124); and forming an emitter electrode (136) on the third semiconductor layer.