A Snapback-Free Reverse-Conducting LIGBT with Embedded Anti-parallel Schottky Barrier Diode

A novel approach to achieving the free-wheeling function in a lateral insulated-gate bipolar transistor (LIGBT) with an embedded anti-parallel floating Schottky barrier diode (FOB) is proposed and investigated using numerical TCAD simulations. The novel snapback-free reverse-conducting LIGBT integrates a FOB, consisting of a floating ohmic contact and a Schottky barrier diode shorted by the floating metal, enabling a reverse conduction path to be obtained by the FOB. Moreover, an oxide layer is embedded between the LIGBT and the Schottky barrier diode (SBD) to completely eliminate snapback and effectively improve the breakdown characteristics, turn-off time, and the trade-off relationship between the on-state voltage drop (V_on) and the turn-off energy loss (E_off). The simulation results show that the proposed FOB-LIGBT reduces the E_off by 41.1%, 44.3%, and 60.4% at V_on of 1.52 V compared with the self-biased n-MOS (SBM), single-trench barrier (STB), and separated shorted anode (SSA) LIGBT designs, respectively. Moreover, the breakdown voltage (BV) of the proposed FOB-LIGBT is 408 V, while the values for the previous SBM-, STB-, and SSA-LIGBT devices are 362 V, 367 V, and 359 V, respectively.