Accumulation layer controlled insulation gate type bipolar transistor

Abstract

Insulated gate bipolar transistors controlled by an accumulation layer belong to the technical field of semiconductor power devices. The transistors include a channel insulated gate bipolar transistor, a plane insulated gate bipolar transistor and a transverse insulated gate bipolar transistor. According to the invention, when a device is in the blocking state, a built-in electric field formed by a P body region (10) and an N base region (4) forms part of an electron barrier which stops electrons flowing from an N source region (9) into the N base region(4) with the voltage-resistance of the device improved; when the device is in the conductive state, the accumulation layer is formed between the N source region (4) and a gate oxide layer (5), and the electrons can flow from the N source region (9) to the N base region (4) through the accumulation layer so as to control the normal operation of the device. With the accumulation layer rather than a P-type base region and an MOS inversion channel of a traditional insulated gate bipolar transistor, the invention can achieve lower conductive voltage drop and greater saturation current density, thereby avoiding parasitic thyristor effect, and ensuring that the safe operating area, the reliability and the high-temperature working characteristics of the device can be greatly promoted.

Description

technical field [0001] An insulated gate bipolar transistor controlled by an accumulation layer belongs to the technical field of semiconductor power devices. Background technique [0002] Insulated gate bipolar transistor is a rapidly developing and widely used power electronic device. It is a new device combined with the advantages of high input impedance of MOSFET, simple driving circuit, high current density and low saturation voltage of bipolar transistor. Now it is widely used in induction cooker, UPS uninterruptible power supply, automotive electronic igniter, frequency converter, motor transmission system and other energy conversion devices. [0003] IGBT was first proposed in 1982 as a punch-through structure, such as figure 1 As shown, it is at high concentrations of P + On the substrate 2, the N-type buffer layer 3, N - The base region layer 4 is fabricated into an insulated gate bipolar transistor structure. Due to the presence of the N-type buffer layer 3, ...

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Problems solved by technology

However, when the trench gate type insulated gate bipolar transistor works at high temperature, on the one hand, due to the increase in temperature, the carrier lifetime increases, and the amplification factor of the PNP transistor becomes larger, resulting in a larger hole current flowing through the P-type base region 8 ; On the other hand, the increase in temperature makes the mobility of holes greatly reduced, and the resistance of the P-type base region 8 increases; both reasons will cause the traditional trench insulated gate bipolar transistor to resist latch-up due to the increase in temperature. The ability is greatly reduced, the safe working area is also reduced, and the reliability is reduced. How to find better high temperature anti-latch-up ability is an urgent problem to be solved

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