Manufacturing method of MOS control thyristor

Abstract

The invention discloses a manufacturing method of an MOS control thyristor. The manufacturing method comprises the following steps: 1) forming an n drift region on the epitaxy of a substrate; 2) forming an n region in the active region; 3) forming a gate oxide layer; 4) depositing a polycrystalline silicon layer and carrying out phosphorus doping; 5) forming a p base region and a terminal p-type field limiting ring; 6) forming an n+ cathode region; 7) forming an n body region and a terminal n-type cut-off ring; 8) forming a p++ source region; 9) flattening the surface; 10) forming a metalizedcathode and a metalized grid electrode; 11) removing the substrate, and taking a transition region formed by convective diffusion between the substrate and the ndrift region as an nFS layer; 12) forming a p+ anode region; 13) forming a multi-layer metallized anode A; 14) forming a cathode and gate pressure welding area isolation pattern and a terminal passivation film; and 15) completing surface protection of the terminal region. The MOS control thyristor manufactured by adopting the method provided by the invention can meet the requirements of the fields of pulse power and solid-state circuitbreakers.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, and relates to a manufacturing method of a MOS control thyristor. Background technique [0002] MOS-controlled thyristors (MCTs) are simpler to drive than ordinary thyristors controlled by current because they are controlled by voltage signals. Although the traditional MCT can reduce the on-state voltage drop of the device, due to the small concentration difference between the p-base region and the n-body region, it is difficult to control the channel concentration and length during manufacturing, which not only leads to channel punch-through when the device is blocked , and the threshold voltage is very sensitive to the change of the channel, which makes the current rise rate low and the on-state voltage drop high during turn-on, thus limiting the wide application of MCT in the fields of pulse power and solid-state circuit breakers. Contents of the invention [0003] The p...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a method for manufacturing MOS controlled thyristors, which solves the problem that it is difficult to accurately control the channel doping concentration and length of the device in the prior art, and cannot meet the application requirements of pulse power and solid-state circuit breakers.

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