Hetero-junction bipolar transistor and a manufacturing method of the same
AssigneeSumitomo Electric Industries, Ltd.
InventorsMasaki Yanagisawa, Hiroshi Yano
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Abstract
This invention provides a hetero-junction bipolar transistor (HBT) having a large base-collector breakdown voltage. The HBT has a collector, a base and an emitter. The emitter is made of a semiconductor material whose band gap energy is greater than that of the base. An passivation layer made of a semiconductor material cover the collector, the base and the emitter and the band gap energy of the passivation layer is greater than that of the collector and the base.
Claims19
A hetero junction bipolar transistor, comprising:
- a collector layer having a band gap energy;
- a base layer having a band gap energy;
- an emitter layer having a band gap energy greater than the band gap energy of the base layer;
- and
- a passivation layer having a band gap energy greater than the band gap energy of the base layer and the band gap energy of the collector layer, the passivation layer being made of a semiconductor material and covering the base layer and the collector layer.
A hetero-junction bipolar transistor, comprising:
- a collector layer having a band gap energy;
- base layer having a band gap energy;
- and
- a passivation layer having a band gap energy greater than the band gap energy of the base layer and the band gap energy of the collector layer, the passivation layer being made of a semiconductor material and covering the base layer and the collector layer,
- wherein the passivation layer serves a function as an emitter layer.
A method for manufacturing a hetero-junction bipolar transistor having a collector layer with a band gap energy, a base layer with a band gap energy and an emitter layer with a band gap energy greater than the band gap energy of the base layer, the collector layer, the base layer and the emitter layer being disposed on a semiconductor substrate, the method comprising the steps of:
- (a) sequentially growing the collector layer, the base layer and the emitter layer on the semiconductor substrate;
- (b) forming a second mesa containing the collector layer, the base layer and the emitter layer;
- and
- (c) growing a passivation layer having a band gap energy greater than the band gap energy of the collector layer and the band gap energy of the base layer, the passivation layer being made of a semiconductor material so as to cover the collector layer, the base layer and the emitter layer, the passivation layer.
A method for manufacturing a hetero-junction bipolar transistor having a collector layer with a band gap energy and a base layer with a band gap energy, the collector layer and the base layer being disposed on a semiconductor substrate, the method comprising the steps of:
- (a) sequentially growing the collector layer and the base layer;
- (b) forming a second mesa containing the collector layer and the base layer;
- and
- (c) growing a passivation layer having a band gap energy greater than the band gap energy of the collector layer and the band gap energy of the base layer, the passivation layer being made of a semiconductor material so as to cover the collector layer, the base layer and the emitter layer, the passivation layer and serving a function of an emitter layer.
Dependencies are inferred from the claim text.