METAL SILICIDE SELF-ALIGNED SiGe HETEROJUNCTION BIPOLAR TRANSISTOR AND METHOD OF FORMING THE SAME

Abstract

The present invention discloses a metal silicide self-aligned SiGe heterojunction bipolar transistor, which is designed to overcome the shortcomings such as the large base resistance RB of the prior art products. The metal silicide self-aligned SiGe heterojunction bipolar transistor of the present invention mainly comprises an Si collector region, a local dielectric region, a base region, a base-region low-resistance metal silicide layer, a polysilicon emitter region, an emitter-base spacer dielectric region composed of a liner silicon oxide layer and a silicon nitride inner sidewall, a monocrystalline emitter region, a contact hole dielectric layer, an emitter metal electrode and a base metal electrode. The base-region low-resistance metal silicide layer extends all the way to the outside of the emitter-base spacer dielectric region. The present invention discloses a method of forming a metal silicide self-aligned SiGe heterojunction bipolar transistor, which is used to form the aforesaid bipolar transistor. The metal silicide self-aligned SiGe heterojunction bipolar transistor and the method of forming the same of the present invention can reduce the base resistance RB, and feature a simple process and a low cost.

Description

BACKGROUND OF THE INVENTION[0001]1. Technical Field[0002]The present invention relates to a metal silicide self-aligned SiGe heterojunction bipolar transistor and a method of forming the same.[0003]2. Description of Related Art[0004]Planar silicon (Si) bipolar transistors are conventional devices for constructing analog integrated circuits (ICs). However, because silicon materials are inherently disadvantageous in speed, group III-V compound (e.g., gallium arsenide) semiconductor devices have always dominated in the field of high-frequency and high-speed applications in the history. For SiGe heterojunction bipolar transistors obtained by introducing narrow-bandgap SiGe alloys into silicon bipolar transistors as materials of base regions, not only the high-frequency performance is improved significantly but also the advantage of the low cost of the silicon-based technology is maintained. Therefore, the SiGe heterojunction bipolar transistors have been widely used in the field of radi...

AI Technical Summary

Benefits of technology

The present invention provides a metal silicide self-aligned SiGe heterojunction bipolar transistor with a simplified process and reduced base resistance. The transistor features a low-resistance metal silicide layer that extends all the way to the outside of the emitter-base spacer dielectric region, which reduces the distance from the base region to the emitter, and a polysilicon elevated extrinsic base region that prevents damage to the monocrystalline base region and reduces the redistribution of impurities doped in the base region. The use of the base-region low-resistance metal silicide layer and the polysilicon elevated extrinsic base region helps to effectively reduce the base and emitter resistance, improve the performance of the device, and reduce manufacturing costs.

Problems solved by technology

However, because silicon materials are inherently disadvantageous in speed, group III-V compound (e.g., gallium arsenide) semiconductor devices have always dominated in the field of high-frequency and high-speed applications in the history.

The former technical solution requires use of expensive special planarization apparatuses and processes; and the latter technical solution may cause process quality control problems (e.g., some defects such as voids may be formed in the linkup base region between the pre-formed extrinsic base region and the intrinsic base region that is grown through the selective epitaxy process) because the intrinsic base region playing a decisive role in the device performance need be grown through the selective epitaxy process which is difficult to control.

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