Super junction structure, super junction mosfet and manufacturing method thereof

Abstract

The invention discloses a super junction structure. A current flow area is composed of P-type columns and N-type columns which are arranged alternately. The P-type columns present non-uniform distribution of impurity, and the N-type columns present uniform or non-uniform distribution of impurity. Finally, in an area close to an N-type heavily doped substrate, the total amount of P-type impurity in the P-type columns is lower than the total amount of N-type impurity in the N-type columns; in an area close to the top of a device, the total amount of P-type impurity in the P-type columns is higher than the total amount of N-type impurity in the N-type columns; and in a quasi charge balance section, the absolute value of the difference between the total amount of impurity in the P-type columns and the total amount of impurity in the N-type columns is smaller than 5% of the total amount of impurity in the N-type columns in the section, and the quasi charge balance section includes a position of complete charge balance. By adopting the super junction structure, the avalanche current tolerance and stability of devices are improved, and the consistency of breakdown voltage of devices is improved. The invention further discloses an MOS field-effect transistor using the structure and a manufacturing method thereof.

Description

technical field [0001] The invention relates to a power semiconductor device, in particular to a super junction semiconductor device. Background technique [0002] A super junction structure is a structure of alternately arranged N-shaped pillars and P-shaped pillars. If the superjunction structure is used to replace the N-type drift region in the VDMOS (Vertical Double-diffused Metal-Oxide-Semiconductor, vertical double-diffused MOS transistor) device, a conduction path is provided in the conduction state (only the N-type column provides a path, The P-type column is not provided), and bears the reverse bias voltage in the off state (the PN column is jointly borne), forming a super junction MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET, Metal-Oxide Semiconductor Field-Effect Transistor) . The super-junction MOSFET can greatly reduce the on-resistance of the device by using a low-resistivity epitaxial layer when the reverse breakdown voltage is consisten...

AI Technical Summary

Problems solved by technology

In this structure, the doping concentration of the top region is too high, which greatly reduces the breakdown voltage of the device (in the case of the same on-resistance)

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