Bipolar transistor having collector with doping spike
AssigneeSkyworks Solutions, Inc.
InventorsPeter J. Zampardi, Jr., Kai Hay Kwok
Life of this patent
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Abstract
This disclosure relates to bipolar transistors, such as heterojunction bipolar transistors, having at a doping spike in the collector. The doping spike can be disposed relatively near an interface between the collector and the base. For instance, the doping spike can be disposed within half of the thickness of the collector from the interface between the collector and the base. Such bipolar transistors can be implemented, for example, in power amplifiers.
Claims18
A bipolar transistor comprising a collector having a first end and a second end opposite the first end, a sub-collector abutting the second end of the collector, a base abutting the first end of the collector at a base-collector junction, and an emitter, the collector having a doping spike disposed closer to the base-collector junction than to the second end of the collector, the doping spike extending substantially an entire length of the collector in a direction substantially parallel to the base-collector junction, and the collector also having a doped portion disposed between the doping spike and the base, the bipolar transistor being a single heterojunction bipolar transistor.
A power amplifier module comprising a power amplifier including a single heterojunction bipolar transistor having a collector, a sub-collector, a base abutting the collector at a base-collector junction, and an emitter, the collector including a doping spike located closer to the base-collector junction than to the sub-collector, the doping spike having a doping concentration of at least about 1×1018 cm−3, the collector further including a doped portion between the base and the doping spike, the power amplifier configured to receive a radio frequency (RF) signal and generate an amplified RF signal from the received RF signal.
A power amplifier die comprising a single heterojunction bipolar transistor having a collector, a base abutting the collector, and an emitter, the collector having a doping spike at a homojunction within about 0.5 μm of an interface between the base and the collector, and the collector having a first portion and a second portion on opposing sides of the doping spike, the first portion being between the doping spike and the base, the second portion being between the doping spike and the sub-collector, the second portion abutting substantially an entire length of one of the opposing sides of the doping spike, and the first portion and the second portion having approximately equal doping concentrations.
Dependencies are inferred from the claim text.