Oblique oxygen manufacturing method of shielding gate groove type MOS transistor

Abstract

The invention relates to the technical field of semiconductors, and particularly discloses an oblique oxygen manufacturing method of a shielding gate groove type MOS transistor. The method comprises the following steps of: providing an epitaxial layer; performing photoetching on the epitaxial layer to obtain a groove; growing an oxide layer along the inner side of the groove; depositing polycrystalline silicon for the first time in the groove after growing the oxide layer; performing ion etching on the first polycrystalline silicon to obtain a triangular polycrystalline silicon side wall residual layer along the side wall of the groove; forming a total oxide layer on the triangular polycrystalline silicon side wall residual layer; depositing secondary polycrystalline silicon on the total oxide layer and performing etching to obtain source polycrystalline silicon; etching the total oxide layer until the total oxide layer is flush with the source polycrystalline silicon; forming an IPO layer on the source polysilicon, and forming a gate oxide layer on the total oxide layer; and depositing polycrystalline silicon for the third time on the IPO layer, and etching to obtain a source electrode and gate electrode double polycrystalline silicon structure of a shielding gate groove. The oblique oxygen manufacturing method of the shielding gate groove type MOS transistor is good in controllability and can be achieved 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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