A fast recovery diode and a manufacturing method thereof

Abstract

The invention relates to a power semiconductor device and a manufacturing method thereof and specifically to a fast recovery diode and a manufacturing method thereof. A junction pushing is performed in an active region in order to form a P+ region and a P region. A junction forming process comprises: firstly performing boron injection in order to push a junction one to ten [mu]m; secondly performing phosphorus compensative injection, wherein a phosphorus injection condition requires that the amount of injected phosphorus only decreases the concentration of the P region close to the silicon surface but not reverses a junction; and performing active region compensative injection to form the P region with low surface concentration. Therefore, the amount of hole injection of the P region in forward conduction is decreased while the concentration on the two sides of a PN junction is guaranteed. When minority carrier lifetime control is used, excessive recombination centers are not required to be generated. Therefore, a series of parameters are optimized. The fast recovery diode and the manufacturing method thereof perform phosphorus compensative injection on the P region so as to achieve the decrease in the surface concentration of the P region. Therefore, the decrease in the number of the hole injection in forward conduction is actually achieved.

Description

technical field [0001] The invention relates to a power semiconductor device and a manufacturing method thereof, in particular to a fast recovery diode and a manufacturing method thereof. Background technique [0002] When a PIN diode conducts forward current, it generally injects a large number of carriers from the anode (P region) and cathode (N+ region) to the drift region (I region), and the hole carriers injected from the anode form a minority in the drift region. store charge in the form of . The minority carrier injection causes the conductance modulation effect in the drift region, thereby reducing the forward on-state voltage drop, which is the biggest advantage of both PIN diodes and bipolar devices. When a reverse voltage is suddenly applied to the conducting diode, the device will not be turned off immediately because a large number of minority carriers are stored in the drift region during conduction. Only when these minority carriers are completely extracted ...

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Problems solved by technology

[0004] 1. Electron irradiation will lead to a large leakage current of the device. Due to the global irradiation, electromagnetic interference (EMI) will be generated during fast di/dt switching; after the device is used for 1-2 years, the defect of electronic irradiation will gradually Recovery, the recovery speed becomes slower, the device characteristics degrade, and the hidden danger of failure is brought to the circuit;

[0005] 2. Au and Pt are commonly used for heavy metals. Au is only used in low-voltage devices below 600V due to its large leakage current; Pt is a good choice for low-voltage devices, but due to the P-type doping effect of Pt, it requires high For devices with resistive materials, the Trr parameter is difficult

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