MOSFET chip manufacturing process for improving grid characteristics

Abstract

The invention discloses an MOSFET chip manufacturing process for improving grid characteristics, which comprises the following steps: removing an isolation oxide layer in a groove region, obtaining first lightly-doped polycrystalline silicon and second lightly-doped polycrystalline silicon on the peripheral side of a groove, heavily doping the lightly-doped polycrystalline silicon in the groove, obtaining first heavily-doped polycrystalline silicon, and removing the residual isolation oxide layer in a body forming region and a source region, close to the groove, of the epitaxial layer; carrying out heavy doping on part of the region of the first lightly-doped polycrystalline silicon, and obtaining second heavy-doped polycrystalline silicon; forming a dielectric layer upwards, wherein the type of the second heavy-doped polycrystalline silicon is opposite to that of the first lightly-doped polycrystalline silicon; and forming a diode by the first lightly doped polycrystalline silicon and the second heavily doped polycrystalline silicon, forming a resistor by two ends of the second lightly doped polycrystalline silicon, and connecting the diode with the resistor in parallel to be connected to the grid electrode in series. The polycrystalline silicon resistor and the polycrystalline silicon diode are integrated in the chip, so that the current flowing through the grid electrode is effectively limited, and the protection on the grid electrode is realized.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a MOSFET chip manufacturing process for improving gate characteristics. Background technique [0002] MOSFET chip is a discrete device, which belongs to the category of semiconductor power devices, and belongs to the field of semiconductor chips with integrated circuits. Integrated circuits integrate thousands of transistors into the same chip through process methods, and MOSFETs are composed of thousands of transistors. A single transistor composed of several cells of the same structure arranged side by side. [0003] The key index parameters of MOSFET include breakdown voltage (specifically drain-source breakdown voltage), on-resistance, threshold voltage and avalanche current. Generally, the larger the breakdown voltage and avalanche current, the better, and the smaller the on-resistance, the better. . In order to achieve its nominal breakdown voltage, an epitaxial la...

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Problems solved by technology

[0006] The invention provides a MOSFET chip manufacturing process with improved gate characteristics, and aims to solve the problem that the existing MOSFET chip cannot effectively limit the current flowing through the gate

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