Thyristor and fabrication method thereof

Abstract

The invention provides a thyristor. The thyristor comprises a first conductive type of substrate, a second conductive type of buried layer, a second conductive type of epitaxial layer, a first conductive type of first injection region, a second conductive type of second injection region, a plurality of first conductive types of third injection regions, an oxide layer, a groove, a first conductivetype of poly-silicon layer and a gate pole metal layer, wherein the buried layer is formed on the substrate, the epitaxial layer is formed on an upper surface of the buried layer, the first injectionregion is formed on an upper surface of the epitaxial layer, second injection region is arranged in the first injection region, the plurality of third injection regions extends from a lower surface ofthe substrate to the substrate at intervals, the oxide layer is arranged at a junction between the first injection region and the second injection region, the groove extends from an upper surface ofthe first injection region to the first injection region and is formed in an outer side of the oxide layer, the poly-silicon layer is filled in the groove, and the gate pole metal layer is arranged atupper surfaces of the first injection region and the poly-silicon layer. The invention also provides fabrication method of the thyristor. The forward voltage drop and the conduction loss of the thyristor are reduced, and the working efficiency and reliability of the thyristor is improved.

Description

technical field [0001] The invention relates to the field of design and manufacture of semiconductor devices, in particular to a thyristor and a preparation method thereof. Background technique [0002] The thyristor is a three-terminal controllable switching device including PNPN four or more semiconductor layers. Its three terminals are the anode, cathode and gate respectively. By controlling the gate, the thyristor can be changed from the cut-off state to the conduction state. It can also change from the on state to the off state. It can control a large current with a small current, so that semiconductor devices can be extended from weak current to strong current. Therefore, thyristors are widely used in electronic circuits such as controllable rectification, AC voltage regulation, non-contact electronic switches, inverters and frequency conversion, and are typical devices for controlling large currents with small currents. [0003] With the development of power electro...

AI Technical Summary

Problems solved by technology

[0003] With the development of power electronics technology, the technical indicators of thyristors include: forward voltage drop, reverse breakdown voltage and turn-off loss. At present, thyristors with traditional structures and processes often only have high reverse breakdown voltage. However, when the shutdown time is long, the loss in the shutdown process is large, which leads to an increase in the power consumption of the entire circuit system, and even cannot work normally at high frequencies.

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