Transistor and manufacturing method thereof

Abstract

The invention relates to a transistor and a manufacturing method thereof. The method comprises the following steps: providing a substrate of a first conductivity type; forming an epitaxial layer of the first conductivity type on the substrate; forming a polysilicon layer of a first conductivity type on the epitaxial layer; removing a polycrystalline silicon layer outside the preset region, whereinthe polycrystalline silicon layer retained in the preset region is an emitter region; forming a first oxide layer on the surface of the emission region; forming a trench on the surface of the epitaxial layer using the first oxide layer as a mask; and forming a diffusion region of a second conductivity type in a surface region of the epitaxial layer exposed by the trench by an ion implantation process. Through a high-temperature annealing process, the impurities in the diffusion region are diffused together under the emitter region to form a base region, and simultaneously, the impurities in the emitter region are diffused to the surface layer of the base region to form an emitter junction; and the transistor formed by the method has a good interface state between the base region and the emitter region, and the amplification coefficient is stable.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a transistor and a manufacturing method thereof. Background technique [0002] In the prior art, the base region is formed by an annealing process after the implantation process, and the junction depth and junction morphology of the base area are greatly affected by the annealing process, while the polycrystalline emitter process is all implanted with a large dose in the polycrystalline body, and then high temperature and rapid Thermal annealing, so that impurities diffuse into the base region to form the emitter junction. On the contact surface of the base region and the emitter region, a large number of processes will be experienced, especially the lithography and etching of the base region window and the lithography and etching of the emitter window, which will bring a large number of defects to the surface of the base region, and finally The amplification factor of th...

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Problems solved by technology

On the contact surface of the base region and the emitter region, a large number of processes will be experienced, especially the lithography and etching of the base region window and the lithography and etching of the emitter window, which will bring a large number of defects to the surface of the base region, and finally The amplification factor of the device is very unstable

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