Temperature sensing diode structure integrated on transistor and its preparation method

Abstract

The invention relates to a temperature sensing diode structure integrated to a transistor and a preparation method of the temperature sensing diode structure. A second oxidizing layer is connected to the upper part of a first polycrystalline silicon layer and comprises an isolation part, the isolation part is isolated downwards to form a diode region, a second polycrystalline silicon layer and an insulating medium layer are sequentially connected to the upper part of the second oxidizing layer, the second polycrystalline silicon layer is isolated into a second diode doping region and an isolation protection ring on the periphery of the second diode doping region by an annular isolation part of the insulating medium layer, the second diode doping region and the isolation protection ring are not connected, and the isolation protection ring is not closed; and the polycrystalline silicon layer extends downwards to be connected with the second diode doping region so as to form a longitudinal PN junction, a first electrode of a diode is connected with the first polycrystalline silicon layer, a second electrode of the diode is connected with the second diode doping region, a protection electrode is connected with the isolation protection ring and is connected with the second electrode to form equal potential. According to the temperature sensing diode structure, the temperature of a chip of the transistor can be detected in real time, and the influences caused by the changing of external currents, voltages, electric fields to a temperature sensing diode can be reduced.

Description

technical field [0001] The invention relates to a temperature sensing diode structure integrated on a transistor and a preparation method thereof, belonging to the technical field of transistors. Background technique [0002] High-current, high-power power semiconductor modules are increasingly used in the automotive field, and protection measures such as over-temperature, over-current, and over-voltage are required for insulated-gate bipolar transistors (IGBTs) or field-effect transistors (MOSFETs). An IGBT or MOSFET needs to be integrated with a temperature sensor. Through the integrated temperature sensor, the temperature of the module and chip can be detected effectively in real time, so as to protect the device in time. At present, most power semiconductor modules package the temperature sensitive element and IGBT or MOSFET chip in the same module, and the temperature sensitive element is to detect the temperature of the circuit and convert the temperature signal into ...

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Problems solved by technology

On the other hand, the polycrystalline thin film diode also needs to be connected to the transistor through an internal circuit, resulting in a complex structure of the power semiconductor module, and it is not fully compatible with transistor processes such as IGBT and MOSFET, which increases the production cost

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