Analysis And Design Of IGBT

IGBT (Insulated gate bipolar transistor) is a Darlington structure composed by MOSFET and bipolar power transistor. It shows many advantages, such as MOSFET's low input impedance, small control power, simple driving circuit, high switching speed, as well as bipolar power transistor's high current density, low saturation voltage, high current processing capability. However, the commercialized IGBT can't be manufactured in our country, most of which are imported from foreign countries. As a result, the research and design of the high performance power device must be paid more attention.According to the structure and work principle of IGBT, the relationship between the structure of IGBT and its characteristics are analyzed theoretically, and the design basis of IGBT's major parameters, such as threshold voltage, forward breakdown voltage and turnoff time, has been summarized. Then the structure parameters of IGBT are designed, strip cell, plane gate, and PT structure are applied in the design. Based on the parameters, the appropriate processes and condition are selected to establish the process model of IGBT.IGBT has three main design indexes, including threshold voltage, the forward breakdown voltage and turnoff time. The transfer characteristic, the on-state characteristic, the switching characteristic and the forward breakdown characteristic of the IGBT are simulated after achieving technical model of IGBT. From the simulating results of IGBT, the forward breakdown voltage is 1450V, threshold voltage is 4.3V, turnoff time is 1.8μs. All performance parameters have met the design requirements. Besides, the IGBT presented in this paper can be well applied in the high voltage power ICs, for its process technics are compatible with the CMOS process technics.