Transverse SiGe heterojunction bipolar transistor with adjustable doping concentration

Abstract

The invention discloses a transverse SiGe heterojunction bipolar transistor with adjustable doping concentration. The transverse SiGe heterojunction bipolar transistor is an NPN type or PNP type transverse SiGe HBT (Heterojunction Bipolar Transistor). By applying a positive voltage to a substrate electrode below an emitter region and a base region of an NPN type device (or applying a negative voltage to a substrate electrode below an emitter region and a base region of a PNP type device), the doping concentration of the emitter region can be increased, the doping concentration of the base region can be reduced, and meanwhile, the current gain and the characteristic frequency can be improved. By applying a negative voltage to a substrate electrode below a collector region of the NPN type device (or applying a positive voltage to a substrate electrode below a collector region of the PNP type device), the doping concentration of the collector region can be reduced, and the breakdown voltage can be improved. Compared with a conventional transverse SiGe HBT, the doping concentrations of the three regions can be independently adjusted by changing the external voltages applied to the substrate electrodes below the emitter region, the base region and the collector region, so that the characteristic frequency, the current gain and the breakdown voltage are synchronously improved.

Description

technical field [0001] The invention relates to a lateral SiGe heterojunction bipolar transistor, in particular to a lateral SiGe heterojunction bipolar transistor with adjustable doping concentration used in the fields of high-speed memory, high-speed emitter-coupled logic circuit, high-speed current type logic circuit and the like. Background technique [0002] The lateral SiGe heterojunction bipolar transistor (HBT) using silicon-on-insulator (SOI) technology not only has the advantages of small substrate parasitic capacitance, low leakage current, and good high-frequency characteristics, but is also compatible with the existing SOI CMOS process , has now played an increasingly important role in the field of microwave power. [0003] figure 1 shows a schematic longitudinal cross-section of a conventional lateral SiGe HBT using SOI technology, mainly composed of Si substrate (10), SiO 2 It is composed of buried oxide layer (11), SiGe base region (12), Si emitter region (...

AI Technical Summary

Problems solved by technology

At this point, the doping concentration levels of the emitter, base, and collector regions of the device become very sensitive and are highly susceptible to semiconductor process variations

Small process deviations will cause large changes in the doping concentration of the emitter, base and collector regions of the device, thereby reducing the current gain, characteristic frequency and breakdown voltage of the device, thereby degrading the electrical performance of the device

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