MOSFET chip manufacturing method for improving grid characteristics

Abstract

The invention discloses an MOSFET chip manufacturing method for improving grid characteristics. The method comprises the following steps: forming lightly-doped polycrystalline silicon on an isolation oxide layer, removing the lightly-doped polycrystalline silicon in a groove region so as to obtain first lightly-doped polycrystalline silicon and second lightly-doped polycrystalline silicon on the peripheral side of the groove region, forming a source region on an epitaxial layer, carrying out heavy doping on a partial region of the first lightly-doped polycrystalline silicon to obtain second heavily-doped polycrystalline silicon, upwards forming a dielectric layer, enabling the type of the second heavily-doped polycrystalline silicon to be opposite to that of the first lightly-doped polycrystalline silicon, forming a diode by the first lightly-doped polycrystalline silicon and the second heavily-doped polycrystalline silicon, forming a resistor is formed by two ends of the second lightly-doped polycrystalline silicon, connecting the diode in parallel with the resistor, and connecting in series with the grid electrode. The polycrystalline silicon resistor and the polycrystalline silicon diode are integrated in the chip, so that the current flowing through the grid electrode can be effectively limited, and the grid electrode can be protected.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for manufacturing a MOSFET chip 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. Usually, 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...

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Problems solved by technology

[0006] The invention provides a method for manufacturing a MOSFET chip 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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