A new trench electrode IGBT having superior electrical characteristics for power IC systems

Abstract

A new small-size Lateral Trench Electrode Insulated Gate Bipolar Transistor (LTEIGBT) is proposed to improve the characteristics of other devices. The entire electrode of the LTEIGBT is replaced with a trench-type electrode. The LTEIGBT is designed so that it has a width of 19 μm. While the latch-up current densities of an LIGBT, LTIGBT and LTEIGBT are 120, 540 and 1230 A cm −2, respectively, that of the proposed LTEIGBT is 10 and two times better than that of the conventional LIGBT and LTIGBT, respectively. The enhanced latch-up capability of the LTEIGBT is obtained due to the fact that the hole current in the device reaches the cathode directly via the p + cathode layer underneath the n + cathode layer. The forward blocking voltage of the LTEIGBT is 130 V, while those of the conventional LIGBT and TIGBT of the same size are 60 and 100 V, respectively. Since the electrodes of the proposed device are of a trench type, the electric field accumulates in the trench oxide of the device. Thus, the punch-through breakdown of LTEIGBT occurs. While the conventional LIGBT and LTIGBT both have a turn-off time of 4 μs, that of the LTEIGBT is 0.2 μs.