How to make high frequency triode

Abstract

The invention relates to a manufacturing method of a high-frequency triode. The manufacturing method includes the following steps: providing an N-type epitaxial layer, sequentially forming a P-type polysilicon and a TEOS dielectric layer on the N-type epitaxial layer; etching the TEOS dielectric layer and the P-type polysilicon, thereby forming a penetrating TEOS dielectric layer and a P Type polysilicon and extend to the emitter groove in the N-type epitaxial layer; form a P-type diffusion region on the surface of the N-type epitaxial layer at the bottom of the P-type polysilicon; The first ion implantation is performed at the bottom, and the direction of the first ion implantation is inclined relative to the side wall on one side of the emitter trench; The second ion implantation, the direction of the second ion implantation is inclined relative to the side wall of the emitter groove side; the third ion implantation is performed on the bottom of the emitter groove by using the emitter groove to form a The emitter junction at the bottom and sidewalls of the trench.

Description

【Technical field】 [0001] The invention relates to the technical field of semiconductor manufacturing technology, in particular, to a method for manufacturing a high-frequency triode. 【Background technique】 [0002] High-frequency triodes are distinguished from ordinary triodes by their small transistor feature size, low breakdown voltage, high characteristic frequency, and difficult manufacturing process. It is generally used in high-frequency broadband low-noise amplifiers such as VHF, UHF, CATV, wireless remote control, and radio frequency modules. These applications are mostly used in low-voltage, small-signal, low-current, and low-noise conditions. [0003] In the existing structure of a high-frequency triode, two kinds of polysilicon are used. One kind of polysilicon is n+ polysilicon layer, which is used to reduce the surface recombination velocity of the base area to improve the injection efficiency of the emitter junction and increase the current gain; on the other ...

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Problems solved by technology

[0004] When the existing high-frequency triode is injected into the base region, under the ideal shape, there is a certain overlap between the base region and the P-type diffusion regions on both sides; under the typical shape, the base region and the P-type diffusion regions on both sides overlap. The stacking area becomes smaller, which will lead to a substantial increase in the resistance of the base region and affect the performance of the device; in extreme process conditions, the base region and the P-type diffusion regions on both sides cannot be effectively connected, resulting in device failure

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