Non-self aligning raising externally basilar space germanium-siliconhetero-junction transistor and technique of preparing the same

Abstract

The invention discloses a non-autoregistration run-up external base region germanium-silicon alloy heterojunction transistor and its preparation process, wherein the heterojunction transistor comprises collector formed by Si underlay, a base region of SiGe layer and an external base region and a polycrystal Si emitter. The sidewall structure layer and run-up external base region layer are set between the emitter and base. The sidewall structure layer prevents creepage between the emitter and base. By the run-up external base region process and the non-autoregistration technology of growing in the extension way, the invention overcomes the shortcomings of serious boron reinforcement and diffusion of the eigen-base region under the emitting area window caused by injection process of the external base region in prior process of germanium-silicon alloy heterojunction transistor, base region broadening, doping change and the parameter decreasing on fT and fmax of the device, which greatly improves the direct current and high frequency characteristic of the device.

Description

technical field [0001] The invention belongs to the technical field of semiconductor devices and their preparation, and in particular relates to a germanium-silicon heterojunction transistor with a non-self-aligned raised extrinsic base region and a preparation process thereof. Background technique [0002] SiGe heterojunction transistors are gradually used in the field of microwave circuits due to their excellent high-frequency performance and low cost advantages. The SiGe heterojunction transistor introduces epitaxial silicon-germanium alloy into the base region to reduce the bandgap width of the base region, thereby greatly improving the DC and high-frequency characteristics of the device. [0003] In the original germanium-silicon heterojunction transistor process, the implantation process is used in the outer base region, and the defects generated by the implantation will lead to serious boron-enhanced diffusion in the intrinsic base region under the emitter window, whi...

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Problems solved by technology

[0003] In the original germanium-silicon heterojunction transistor process, the outer base region adopts the implantation process, and the defects generated by the implantation will lead to serious boron-enhanced diffusion in the intrinsic base region under the emitter window, which will cause the base region to widen and the doping to change. , while reducing the f of the device T and f max and other parameters

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