Reverse conducting insulated gate bipolar transistor

Abstract

The invention provides a reverse conducting insulated gate bipolar transistor. The reverse conducting insulated gate bipolar transistor comprises an N type substrate, a front-surface structure formed at the front surface of the N type substrate and a back-surface structure formed at the back surface of the N type substrate; the back-surface structure comprises grooves formed at the back surface of the N type substrate, back-surface P+ regions formed between the grooves, polysilicon arranged in the grooves and a back-surface metal layer which is formed on the back-surface P+ regions and the polysilicon. According to the reverse conducting insulated gate bipolar transistor, the polysilicon is adopted to fill the grooves at the back surface of the reverse conducting insulated gate bipolar transistor. When the reverse conducting insulated gate bipolar transistor is manufactured, it only needs to precisely control the doping concentration of the polysilicon so that the parameters of a reverse conducting diode at the back surface of the reverse conducting insulated gate bipolar transistor can be controlled, and process control requirements are low. The reverse conducting insulated gate bipolar transistor has the advantages of low manufacturing process control requirements and low manufacturing difficulty.

Description

technical field [0001] The invention relates to a semiconductor element, in particular to a reverse conducting insulated gate bipolar transistor. Background technique [0002] An insulated gate bipolar transistor (IGBT, Insulated Gate Bipolar Transistor) is a commonly used power switching device controlled by voltage. It has the characteristics of large input capacitance, high input impedance, small driving current, fast speed, high withstand voltage, strong thermal stability, high operating temperature, and simple control circuit. It has become the mainstream device of power electronic devices at this stage. The reverse conducting insulated gate bipolar transistor is a new type of IGBT device, which integrates the IGBT structure and the reverse conducting diode structure on the same chip. This can improve the passage of non-equilibrium carriers and optimize the tail current. Reverse conducting IGBT devices have many advantages such as small size, high power density, low c...

AI Technical Summary

Problems solved by technology

The manufacturing method of the reverse conducting diode structure of the reverse conducting IGBT mainly adopts the method of digging and filling the back metal to form the reverse conducting diode structure, but the metal in the back groove of the reverse conducting IGBT is limited by the reverse conducting IGBT collector. Metal requirements, the parameters of the reverse conducting diode can only be adjusted by adjusting the width and depth of the trench, the process adjustment is troublesome, and the process control requirements are high

Therefore, from the above two process methods, it can be seen that the manufacturing method of the reverse conducting diode structure on the back of the common reverse conducting IGBT device requires high manufacturing process control and is difficult to manufacture.

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