A kind of oblique oxide manufacturing method of shielded gate groove type MOS tube

Abstract

The invention relates to the field of semiconductor technology, and specifically discloses a method for manufacturing a shielded gate trench type MOS transistor, which includes: providing an epitaxial layer; performing photolithography on the epitaxial layer to obtain a groove; grow a layer of oxide layer; deposit the polysilicon for the first time in the trench after growing the oxide layer; carry out ion etching to the polysilicon for the first time to obtain the triangular polysilicon sidewall residual layer along the sidewall of the trench; place the triangular polysilicon sidewall The residual layer forms a full oxide layer; deposit a second polysilicon on the full oxide layer and etch to obtain the source polysilicon; etch the full oxide layer until it is flush with the source polysilicon; form an IPO layer on the source polysilicon, And forming a gate oxide layer on the full oxide layer; depositing polysilicon for the third time on the IPO layer, and etching to obtain a source and gate double polysilicon structure of the shielded gate trench. The oblique oxide manufacturing method of the shield gate trench type MOS transistor provided by the present invention has good controllability and can be realized without adding too many process steps.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for manufacturing a shield gate trench type MOS transistor. Background technique [0002] With the rise of mobile phone fast charging, electric vehicles, brushless motors and lithium batteries, the demand for power metal-oxide-semiconductor field-effect transistors (MOSFETs) is increasing, and the requirements for low resistance are also increasing. As far as the trench structure is concerned, its resistance value can no longer meet the requirements of the terminal. Shielding Gate Trench (SGT) structure, such as figure 1 As shown, in recent years, the traditional trench structure has been widely replaced. The PN junction of the shielded gate trench structure converts its electric field from the triangular area of ​​the traditional trench to the trapezoidal area when the device is reverse biased, which shows that the device is in Under the same breakdown voltage,...

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Problems solved by technology

[0006] The invention provides a method for manufacturing oblique oxygen of shielded gate trench type MOS transistors, which solves the problems of cumbersome manufacturing steps and difficult control of the oblique oxide layer in the related art

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