Investigation in characteristics of 1200V vertical IGBT for different trench designs

In this paper, we investigate the behavior of 1200V Punch-Through, Trench gate, Field stop (FS) IGBT at various temperatures for different trench widths and depths. MOS-controlled devices with trench gates are the most desirable as their reduced V_CE(sat) enables increased conduction current density in high power applications. The paper describes the simulation results of the trench gate IGBT. The effect caused in the I-V characteristics of IGBT by the trench design has been investigated for the first time. The results have been compared with different trench sizes. Technology-computer-aided-design (TCAD) simulations with Sentaurus and analytical solution reveal that the breakdown occurs under the gate. By enlarging the gate length, more freedom for conductivity modulation is provided decreasing the conduction losses. Trench gates provide higher channel density (small cell size) and reduce the JFET resistance in the IGBT structure. It is observed that the variation in trench width and depth affects the breakdown voltage, V_CE(sat) and switching characteristics in turn varying the stability of the device. This device design not only reduces the chip size, but also improves current handling capability and latch-up current density.