Insulated gate bipolar transistor

Abstract

The invention discloses an insulated gate bipolar transistor (IGBT), belonging to the technical field of power semiconductor devices. According to the invention, impurities in a deep energy level (12) with an acceptor level are introduced into a P+ conductor region (6) of the traditional insulated gate bipolar transistor through an ion implantation or impurity diffusion manner. At the room temperature, only a small part of the impurities in the deep energy level (12) imported into the P+ conductor region (6) are ionized, so that the impact on the positive conduction work of the device can be ignored. When large current flows inside the device and the heat loss of the device increases, the ionization rate of the impurities in the deep energy level (12) can increase along with the rising temperature of the device, so that the effective doping concentration of a base region of an NPN tube in a parasitic NPNP thyristor structure in the IGBT device can be increased, the injection efficiency gamma of an emitter of the NPN tube can be reduced, then, the amplification coefficient alpha NPN of a common base of the NPN tube can be reduced, and the consequence that the parasitic thyristor of the device is opened when alpha NPN plus alpha PNP is more than or equal to 1 so that the device can be finally burnt out for the device cannot be turned off due to the loss of grid control ability can be avoided, thereby finally achieving the purpose of enlarging the positive safety work area of the device and improving the reliability of the device.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, and relates to an insulated gate bipolar transistor (IGBT) device structure and a preparation method thereof. Background technique [0002] Insulated gate bipolar transistor (IGBT) is a new type of power semiconductor device. It not only has the advantages of high input impedance, low driving power, simple driving circuit and high switching speed of MOSFET, but also has the advantages of high current density, low saturation voltage and strong current handling ability of bipolar transistor. Therefore, IGBT has three characteristics of high voltage, high current and high speed, which are unmatched by other power devices. As a power switching tube or power output tube, IGBT is widely used in induction cooker, UPS uninterruptible power supply, automotive electronic igniter, three-phase motor inverter, welding machine switching power supply and other products, and has become one o...

AI Technical Summary

Problems solved by technology

When the sum of the common base amplification factors of the two transistors is greater than 1, that is, α NPN +α PNP When ≥1, it will trigger the opening of the parasitic thyristor in the IGBT, and a latch-up effect will occur, causing the device to lose its gate control capability and cannot be turned off. temperature and positive safe operating area

[0004] A common method to improve the reliability of IGBT devices is to use a self-aligned process to form a P + The body region 6 is used to reduce the lateral resistance and the common base amplification factor of the parasitic NPN transistor in the P-type base region 5, but the P + The implant dose and energy of body region 6 should not be very large

If the implantation energy is too large, the masking effect of the polysilicon gate electrode 10 and the gate oxide 9 may fail; due to the self-alignment process for implantation, the implantation dose is too large, which may lead to P + The body region 6 extends seriously to the channel region, which will seriously affect the threshold voltage and turn-on energy of the device

This also limits the further improvement of device reliability by this method

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