Insulated gate bipolar transistor and preparation method thereof

Abstract

The invention discloses an insulated gate bipolar transistor and a preparation method thereof. The preparation method comprises the following steps that: a first conductive type semiconductor layer isformed on the back surface of a substrate, and an MOS structure is formed on the front surface of the substrate; grooves which are arranged at intervals are formed on the first conductive type semiconductor layer; a first part of a second conductive type collector region is formed in the grooves; and a second part of the second conductive type collector region is formed in the first conductive type semiconductor layer and the grooves, the first part of the second conductive type collector region and the second part of the second conductive type collector region form the second conductive typecollector region. According to the insulated gate bipolar transistor and the preparation method thereof provided by the embodiments of the invention, the groove type design is added to the collectorregion of the IGBT; and the groove type structure enables the IGBT to keep an active region to have enough carrier concentration during the work of the IGBT, and reduces the carrier concentration of aterminal region, and therefore, the injection efficiency of the collector region can be optimized, the reverse bias safety working region of the device can be improved; and the groove structure is more beneficial to metal adhesion, and therefore, the metal structure of the surface of the back collector of the IGBT can be optimized.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to an insulated gate bipolar transistor and a preparation method thereof. Background technique [0002] As a new type of power electronic device, insulated-gate bipolar transistor (IGBT) has the advantages of high input impedance, simple drive circuit, on-state voltage drop, wide safe operating area, strong current handling capability, and good thermal stability. The IGBT device is developed on the basis of the power MOSFET structure. In contrast, the IGBT has a larger current density, lower power loss, and there is no parasitic reverse diode inside the IGBT, which makes the IGBT more efficient. The application is more flexible. [0003] At present, IGBT devices continue to develop in the direction of high voltage and high current, especially as the voltage level increases, the thickness of the IGBT substrate increases, and the saturation voltage drop of the device increases...

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Problems solved by technology

[0004] In view of this, an embodiment of the present invention provides an insulated gate bipolar transistor and a manufacturing method thereof to solve the problem of narrowing of the reverse bias safe operating area of ​​the device and deterioration of the robustness of the device in the case of high voltage and high current of the IGBT in the prior art technical issues

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