Germanium-silicon heterojunction bipolar transistor and manufacturing method

Abstract

The invention discloses a germanium-silicon heterojunction bipolar transistor. A base region is defined by a base region window formed after photoetching and etching of a base region window substratelayer comprising a first polycrystalline silicon layer, a P-type germanium-silicon epitaxial layer forming the base region is formed by a comprehensive nonselective epitaxial growth technology, and apolycrystalline structure, positioned on the side surface of the base region window, of the P-type germanium-silicon epitaxial layer is in contact with the first polycrystalline silicon layer to formouter base region polycrystalline silicon; an emitter region window is defined in a self-alignment manner through a first side wall formed on the side face of the base region window in the self-alignment manner, and emitter region polycrystalline silicon is formed by filled second polycrystalline silicon and a second substrate layer on the top of the base region window substrate layer as a terminating layer after polycrystalline silicon grinding. The invention also discloses a manufacturing method of the germanium-silicon heterojunction bipolar transistor. The process cost of the P-type germanium-silicon epitaxial layer can be reduced to be lower, the resistance of the base region can be reduced, the transverse dimensions of the whole device are reduced, and the maximum oscillation frequency of the device can be improved.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit manufacturing, in particular to a silicon-germanium (SiGe) heterojunction bipolar transistor (HBT); the invention also relates to a method for manufacturing the silicon-germanium heterojunction bipolar transistor. Background technique [0002] UHF RF applications require improved characteristic frequency (f t ) and the highest oscillation frequency (f max ). The characteristic frequency is also called the cut-off frequency, which is the frequency when the current gain is 1; the highest oscillation frequency is the frequency when the power gain is 1. Lower base resistance (R B ) and base-collector capacitance (C BC ) can reduce f max . [0003] In the existing SiGe HBT, taking the NPN transistor as an example, P-type polysilicon is usually used to raise the outer base region, and a self-aligned device structure with an inner wall is used between the emitter and the outer base r...

AI Technical Summary

Problems solved by technology

[0024] The existing first method is relatively simple, but requires selective germanium-silicon epitaxy, that is, the P-type germanium-silicon epitaxial layer 11 needs to be formed by selective germanium-silicon epitaxy growth. The P-type SiGe epitaxial layer 11 has challenges

[0025] However, the existing second method adopts the non-selective epitaxial process of silicon germanium to grow the P-type silicon germanium epitaxial layer 206, but in the end, it needs to grow selectively in the regions other than the sidewalls 210 and 213 of the polysilicon (EP) 211 in the emission region. highly doped polysilicon, it is also difficult

Images