A kind of manufacturing method of high voltage fast soft recovery diode

Abstract

The invention discloses the manufacturing method of a high-voltage fast soft recovery diode. The method comprises the following steps of carrying out phosphorus ion implantation on the lower surface of a silicon wafer, after oxidation and high temperature propulsion, forming a n buffer layer possessing a deep junction and a low-doped concentration gradient; then, carrying out boron ion implantation on an upper surface, after oxidation propulsion, forming a p anode area, a p resistor area and a plurality of p field limiting rings of a terminal area; and then, through the pre-deposition of impurity phosphor, forming a n+ cut-off ring and a n+ cathode area on the upper surface and the lower surface; and after a chip is completed, successively adopting low energy electron irradiation and highenergy hydrogen ion local irradiation on an anode side so as to acquire special minority carrier lifetime distribution. A high-voltage diode manufactured by using the method of the invention has a high breakdown voltage and a fast and soft reverse direction recovery characteristic, current concentration at the edge of an active area can be well alleviated, a dynamic avalanche resistance capabilityis increased, and high reliability is possessed.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, and relates to a manufacturing method of a high-voltage fast soft recovery diode. Background technique [0002] With the rapid development of insulated gate bipolar transistor (IGBT) modules, the performance requirements for freewheeling diodes are getting higher and higher. Not only are the diodes required to have high withstand voltage, low loss, fast and soft reverse recovery characteristics, Moreover, it has high reliability and low cost, so the research and development of high-voltage fast soft recovery diode (FSRD) is very urgent. [0003] In order to obtain fast recovery characteristics, FSRD usually adopts two methods: one is to reduce the number of carriers injected into the n-region during conduction by reducing the doping concentration or thickness of the anode region and reducing the thickness of the n-region; However, reducing the thickness of the n-region is not...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a method for manufacturing high-voltage fast soft recovery diodes (FSRD), which solves the problem that under the existing technical conditions, there is no complete and scientific process design in the production process of high-voltage fast soft recovery diodes, and performance and reliability cannot be taken into account. Sexuality, which affects the quality of high-voltage fast soft recovery diodes

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