IGBT with improved collector structure

Abstract

The invention relates to an insulated gate bipolar translator (IGBT) with an improved collector structure. The IGBT comprises a semiconductor substrate, wherein the second main surface of the semiconductor substrate is provided with a second conductive type collecting region and a metalized collector; a second conductive type base region is arranged in the semiconductor substrate; the upper part of the second conductive type base region is provided with a first conductive type emitting region; the first main surface of the semiconductor is provided with an insulated gate, an insulated dielectric layer and a metalized emitter; the second conductive type collecting region comprises one or more first regions with a first doping density and one or more second regions with a second doping density; the first regions surround the plurality of the second regions or the first regions and the second regions are arranged alternately and adjacently; the first doping density of the first regions is less than the second doping density of the second regions; and the first doping density of the first regions is greater than the doping density of the first conductive type conductive substrate. TheIGBT has the characteristics of low on-state voltage, lower turn-off loss and higher impact resistance performance.

Description

technical field [0001] The invention relates to a power semiconductor device, in particular to an IGBT with an improved collector structure. Background technique [0002] The insulated gate bipolar transistor IGBT (Insulated Gate Bipolar Transistor) was proposed and rapidly promoted in the 1980s, and has been widely used in the field of medium and high voltage and high current. ) pushes power electronics technology to the high frequency era, compared with other kinds of power semiconductors, such as bipolar transistors and MOSFETs; the insulated gate bipolar transistors can handle higher power with lower power loss, and can Working in high-frequency circuits is the most prominent feature and advantage of IGBT. At present, the types of IGBTs that have been widely produced and used include: punch-through IGBT (PT-IGBT), non-punch-through IGBT (NPT-IGBT), and field-stop IGBT (FS-IGBT). The original intention and goal of reducing power loss and increasing operating frequency w...

AI Technical Summary

Problems solved by technology

The denser the doping concentration of the P-type collector region, the higher the injection efficiency of the P-type collector region as the emitter region of the PNP bipolar transistor when the IGBT is in the forward conduction state, and the greater the hole current will be. , so that the on-state voltage drop will be lower; however, due to the increase in injection efficiency, the reverse recovery charge, reverse recovery time and tail current of the device will all increase, increasing the power loss when the device is turned off, and , due to the very large concentration gradient between the P-type collector region and the N-type drift region, the number of minority carriers injected into the P-type collector region is very limited, and these minority carriers are quickly swept away during the reverse recovery process. Out or compound, increase the hardness of reverse recovery, that is, the S value is small, reducing the impact resistance of the device

On the contrary, if the impurity concentration of the P-type collector area is reduced, the on-state voltage drop of the device will increase, resulting in an increase in on-state loss, which is also not conducive to device performance.

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