Thyristor gate-cathode junction and method for preparing gate-commutated thyristor with the structure

Abstract

The invention discloses a preparation method of a thyristor gate cathode junction and a preparation method of a gate commutated thyristor with the thyristor gate cathode junction. The preparation method of the thyristor gate cathode junction comprises the following steps of preparing an N-type substrate, conducting selective P+ diffusion treatment on the front surface of the N-type substrate to form a P+ short base region, conducting P diffusion treatment on the front surface of the N-type substrate to form a P base region, conducting N+ predeposition treatment to form an N+ layer, conducting gate etching treatment to etch off the N+ layer above a gate, conducting N+ boosting treatment on the N+ layer to form the gate cathode junction in a double-step structure, and conducting metal deposition and etching treatment to form a cathode metal electrode and a gate metal electrode respectively. According to the preparation methods of the thyristor gate cathode junction and the gate commutated thyristor with the thyristor gate cathode junction, the recombination of electrons injected into an N+ emitting region of the thyristor in the P+ short base region and the P base region can be reduced, a conductive modulation effect of the thyristor is improved, and the breakover current and breakover speed of the thyristor can be further increased.

Description

technical field [0001] The invention relates to a method for preparing a semiconductor device, in particular to a thyristor gate-cathode junction structure applied in the field of power semiconductors and a method for preparing a gate commutation thyristor with the structure. Background technique [0002] Silicon is a kind of semiconductor material. The semiconductor devices represented by silicon are all processed on the basis of the original single crystal. By doping a small amount of impurities into it, the conductivity is significantly changed, thereby forming a specific structure and doping. Miscellaneous distribution, so as to realize the function of the device. The dopants are divided into two categories: one is N-type dopants, such as phosphorus and arsenic atoms. The other type is P-type dopants, such as boron, aluminum and gallium atoms. Doping phosphorus, arsenic, and antimony can make silicon an electron-conducting type (N-type) silicon, and doping boron, alumi...

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Problems solved by technology

[0010] attached by image 3 It can be seen that although the gate-cathode junction structure in the prior art and the thyristor with this structure have a large amount of electron injection from the N+ emitter region 6, due to the high doping concentration of the P+ short base region 5, a large amount of electrons are provided. The electrons recombine with the holes here to reduce the electron injection amount of the P-base region and the N-base region, which becomes a factor limiting the conductance modulation effect

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