A composite trench discrete gate power device and its manufacturing process

By adopting a T-shaped composite trench structure and discrete gate polysilicon filling method, the problems of large short-circuit current and complex process of traditional trench gate power devices under high voltage are solved, and the device's breakdown resistance and gate capacity are improved.

CN112436055BActive Publication Date: 2025-07-01VANGUARD SEMICON CORP
View PDF 3 Cites 0 Cited by

Patent Information

Application Number
CN202011427090.4
Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Filing Date
2020-12-09
Publication Date
2025-07-01
Estimated Expiration
2040-12-09

AI Technical Summary

Technical Problem

Traditional trench gate power devices have large short circuit current under high voltage, resulting in a sharp rise in device temperature and damage; there are poor groove morphology during trench etching and thickness uniformity during gate oxygen preparation in process.

Method used

Using a T-shaped composite trench structure, deep trench and shallow trench are formed in combination. The first gate oxygen layer grows on the inner wall of the deep trench, the gate polysilicon is filled to the shallow trench, the second gate oxygen layer grows on the inner wall of the shallow trench and the outer wall of the polysilicon is filled, and the discrete gate polysilicon is filled.

Benefits of technology

The device's anti-avalanche breakdown capability is improved, and the leakage problem is improved, combined with the advantages of planar gate and trench gate, the gate capacity is improved.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN112436055B_ABST
    Figure CN112436055B_ABST
Patent Text Reader

Abstract

The present invention discloses a composite trench discrete gate power device and its manufacturing process. The power device includes a T-shaped composite trench structure formed by combining a deep trench and a shallow trench. The shallow trench is formed above the deep trench and has a width greater than that of the deep trench. A first gate oxide layer is grown on the inner wall of the deep trench, and gate polysilicon is filled on the first gate oxide layer of the deep trench and extends above the shallow trench. A second gate oxide layer is grown on the inner wall of the shallow trench and the outer wall of the gate polysilicon layer in the shallow trench, and discrete gate polysilicon is filled on the second gate oxide layer of the shallow trench. Its manufacturing process mainly adopts the method of etching the deep trench and the shallow trench in sequence. The present invention solves the problem of poor avalanche breakdown resistance of the traditional trench gate; improves the problem of leakage current increase of the traditional trench gate; adopts a discrete gate structure, combines the advantages of the planar gate and the trench gate, and improves the gate capacitance.
Need to check novelty before this filing date? Find Prior Art

Citation Information

Patent Citations

  • Shield gate trench power device and fabrication method thereof

    CN106298941A

  • Deep shallow trench semiconductor power device and preparation method

    CN108447911A

  • Composite trench discrete gate power device

    CN213459740U