Manufacturing method and device of shielded gate trench type field effect transistor

Abstract

The manufacturing method and device of the shielded grid trench type field effect transistor, the field plate is preliminarily designed, and then the electric field is finely adjusted by injecting doping through design, and finally the actual shielded grid trench field is performed according to the finely adjusted field plate and doping structure. Effect tube production; the preliminary design of the field plate is a stepped type with a large top and a small bottom. Implantation and doping include part of the side wall implantation, and the implantation position corresponds to the upper step layer of the stepped field plate. Simulation and debugging of the implanted doping position, material and concentration until the desired electric field is obtained. The schemes in the prior art are more complex in terms of adjusting the electric field, but the present invention can easily optimize and adjust the electric field shape to obtain the best value through a simple implantation and doping method, the process is simple, and the production cost is also controlled.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, relates to a shielding gate trench type field effect transistor SGT, and relates to a manufacturing method of a shielding gate trench type field effect transistor and a device thereof. Background technique [0002] In recent years, as a new technology of MOSFET, shielded gate trench field effect transistor SGT MOSFET has received more and more attention. In the research and development of SGT devices, how to increase the breakdown voltage BVDSS is a problem that needs to be improved. In the traditional SGT structure, the thickness of the oxide layer in the lower half of the trench is uniform, such as figure 1 As shown, the corresponding electric field result is as figure 2 As shown, the area of ​​the electric field is the potential BV, the electric field has two peaks 1 and 3, and the middle part 2 needs to be improved. Traditional SGT has poor utilization of epitaxy, and its electric ...

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Problems solved by technology

[0007] The problem to be solved by the present invention is: the improvement of the SGT MOSFET electric field in the prior art is mostly realized by designing the structure of the polysilicon field plate, but a large amount of engineering resources and time need to be spent between the design of the field plate structure and the production of the real process, and the product development time long, expensive

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