IGBT device with built-in temperature sensor and preparation method thereof

Abstract

The invention provides an IGBT device with a built-in temperature sensor and a preparation method thereof.The IGBT device comprises a temperature sensor part and an IGBT part, the IGBT part comprises an IGBT chip, the temperature sensor part is located in an accompanying area of the IGBT chip, the temperature sensor part comprises an N-type polycrystalline silicon area, a P-type polycrystalline silicon area, a gate oxide layer, a dielectric isolation layer and a metal layer, and the N-type polycrystalline silicon area, the P-type polycrystalline silicon area, the gate oxide layer, the dielectric isolation layer and the metal layer are located in the accompanying area of the IGBT chip. The IGBT part comprises a cellular area and a terminal area; the side walls of the N-type polycrystalline silicon region and the gate oxide layer comprise a plurality of lug bosses, and the plurality of lug bosses are in one-to-one correspondence. According to the invention, the side wall of the polycrystalline silicon diode (temperature sensor) is designed into a convex structure, so that in a gate oxide growth process, a local gate oxide layer thinning effect can be formed at the position of a convex corner or a concave corner of the side wall, and meanwhile, the opposite contact area between the polycrystalline silicon diode and an IGBT chip active region is also increased by the convex structure; the conductive thermal resistance is reduced, and the temperature measurement accuracy of the diode temperature sensor is improved.

Description

Technical field [0001] The invention relates to the technical field of IGBT device preparation, and in particular to an IGBT device with a built-in temperature sensor and a preparation method thereof. Background technique [0002] IGBT is a high-power semiconductor discrete device that combines the advantages of high switching frequency and easy control of MOS devices with the high current processing capabilities of BJT devices. It has applications in industrial frequency conversion, consumer electronics, rail transportation, new energy, aerospace and other fields. Wide range of applications. As the core component of the power electronic system, excessive temperature will cause damage to the IGBT chip, and excessive temperature fluctuations will also shorten its service life. Therefore, in order to better utilize the performance of the IGBT chip, it is necessary to integrate a temperature monitoring sensor inside the chip. , monitor its temperature in real time. [0003] A...

AI Technical Summary

Problems solved by technology

However, due to the insulating effect of the gate oxide layer, the conduction thermal resistance between the active area of ​​the IGBT chip and the temperature measuring diode is increased. From the perspective of material thermal conductivity, the thermal conductivity of silicon dioxide is lower than that of single crystal silicon. Therefore, even a very thin gate oxide layer will greatly increase the thermal resistance on the heat conduction path, so that the temperature of the polysilicon diode area cannot truly reflect the active area of ​​the chip The temperature will affect the effect of chip temperature monitoring

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