Heterojunction bipolar transistor and method of manufacturing the same
AssigneeNEC Corporation
InventorMasahiro Tanomura
Life of this patent
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Abstract
A heterojunction bipolar transistor comprises a collector layer, a base layer, and an emitter layer stacked sequentially. The base layer comprises a first base layer joined to the collector layer in an inward base area directly below the emitter layer and a second base layer joined to the collector layer in an outward base area adjacent to the inward base area. The second base layer is formed of a semiconductor with a wider energy band gap than the collector layer.
Claims6
A heterojunction bipolar transistor comprising a collector layer, a base layer, and an emitter layer sequentially stacked, wherein said base layer includes a first base layer joined to said collector layer in an inward base area directly below said emitter layer and a second base layer joined to said collector in an outward base area adjacent to said inward base area, said second base layer being formed of a semiconductor with an energy band gap wider than said collector layer.
A method of manufacturing a heterojunction bipolar transistor comprising:
- a first step of sequentially stacking a collector layer, a first base layer, and an emitter layer;
- a second step of removing said first base layer in an outward base area adjacent to an inward base area directly below said emitter layer and a portion of said collector layer directly below said outward base area;
- and
- a third step of forming an insulating film made of a predetermined material on the entire surface of said inward base area to sequentially form a second base layer made of a semiconductor with a wider energy band gap than said collector layer and said first base layer on said collector layer from which said portion has been removed in said second step through selective re-growth by using said insulating film.
A method of manufacturing a heterojunction bipolar transistor comprising:
- a first step of sequentially stacking a collector layer and a first base layer made of a semiconductor with a wider energy band gap than said collector;
- a second step of forming an insulating film made of a predetermined material on the entire surface of said first base layer and removing said first base layer in an inward base area directly below an emitter layer to be formed on said first base layer and said insulating film on said inward base area to expose a surface of said collector layer;
- a third step of forming a second collector layer on the surface of said collector layer exposed in said second step through re-growth;
- and
- a fourth step of removing said insulating film and then sequentially forming a second base layer made of a predetermined material and said emitter layer made of a semiconductor with a wider energy band gap than said second base layer through re-growth.
Dependencies are inferred from the claim text.