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US 11,557,664 B2Granted
Heterojunction bipolar transistor including ballast resistor and semiconductor device
AssigneeMurata Manufacturing Co., Ltd.
InventorsIsao Obu, Yasunari Umemoto, Takayuki Tsutsui, Satoshi Tanaka
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Abstract
A first sub-collector layer functions as an inflow path of a collector current that flows in a collector layer of a heterojunction bipolar transistor. A collector ballast resistor layer having a lower doping concentration than the first sub-collector layer is disposed between the collector layer and the first sub-collector layer.
Claims10
A semiconductor device comprising, in sequence:
- a substrate;
- a first sub-collector layer;
- a collector ballast resistor layer having a lower doping concentration than the first sub-collector layer;
- a second sub-collector layer having a higher doping concentration than the collector ballast resistor layer;
- a collector layer;
- a base layer;
- and
- an emitter layer,
- wherein, in a first region within a plane of the substrate, the first sub-collector layer, the collector ballast resistor layer, the second sub-collector layer, the collector layer, the base layer, and the emitter layer form a first heterojunction bipolar transistor,
- a collector electrode of the first heterojunction bipolar transistor is connected to the first sub-collector layer,
- in a second region different from the first region, at least the second sub-collector layer, the collector layer, the base layer, and the emitter layer form a second heterojunction bipolar transistor, and
- the semiconductor device further includes an interconnection line that connects the collector layer of the second heterojunction bipolar transistor to the emitter layer of the first heterojunction bipolar transistor.
9 more elements
Dependencies are inferred from the claim text.