Method for controlling defect level of PN junction based on electron irradiation

Abstract

The invention discloses a method for controlling a defect level of a PN junction based on electron irradiation. The method comprises the steps of (1) performing a baseline experiment prior to primary processing and grouping devices according to an irradiation condition; (2) performing irradiation processing on the devices according to the irradiation condition and fixing an irradiation direction, an irradiation environment and a cooling system; (3) storing the devices at normal temperature and pressure to achieve stable properties; (4) testing DLTS (Deep Level Transient Spectroscopy) and determining position, concentration and capture cross section parameters of the defect level; (5) testing electrical characteristic parameters which include a forward characteristic, a reverse characteristic and a switching characteristic; and (6) performing massive processing and production. The method can control the position and concentration parameters of the defect level by changing the electron irradiation condition, is good in repeatability, can achieve the massive processing after early testing, and can realize an objective of oriented optimization for various properties of the devices according to a production demand.

Description

technical field [0001] This technology relates to the field of radiation modification. It is mainly used to control the defect energy level parameters in PN junctions by electron irradiation. Background technique [0002] As the operating frequency of power switching devices continues to increase, the requirements for switching speed and comprehensive performance of fast recovery diodes connected in parallel with them are also increasing. Electron irradiation modification technology has replaced gold-doped and platinum-doped technology and has become one of the commonly used device performance optimization technologies because of its advantages of good consistency, simple process, and low cost. The main goal of diode performance optimization is to use different lifetime control technologies, by introducing defect energy levels in the forbidden band as recombination centers, thereby reducing the lifetime of minority carriers and increasing the switching speed, while ensuring...

AI Technical Summary

Problems solved by technology

But the key that actually affects the performance of the irradiated device is the position and concentration of the defect level introduced into the PN junction. The closer the position of the defect level to the center of the forbidden band, the higher the defect concentration, the more obvious the recombination effect, and the shorter the minority carrier lifetime of the device. Low, but other performance degradation is more serious

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