A Snapback-Free RC-LIGBT Integrated With Three-Mode Self-Adaptive nMOS for Improved Performance and Reliability

Abstract

A Reverse-Conducting LIGBT integrated with three-mode Self-Adaptive n-channel MOS (SAM), named SAM-LIGBT, is proposed. SAM-LIGBT consists of a control region and a conduction region. The control region is equivalent to two diodes connected in reverse series, with its P+ regions on both sides connected to the Collector and Emitter, respectively. When the Collector or Emitter voltage rises, the potential of the N-drift and buffer regions increases accordingly. The rise in N-drift potential creates an electron accumulation effect on both sides of the conduction region. The rise in buffer potential provides the gate voltage for the SAM. 1) During forward conduction, the SAM turns on, and the electron accumulation effect enhances electron injection efficiency. Meanwhile, the P-base substrate of the SAM acts as an electron barrier, eliminating the snapback phenomenon; 2) During reverse conduction state, the SAM turns on, providing reverse conduction capability; 3) During the turn-off process, the SAM turns on to form an electron extraction channel, accelerating electron removal, thereby shortening the turn-off time $t_{\mathrm {OFF}}$ and reducing the turn-off loss $E_{\mathrm {OFF}}$ . Additionally, the SAM improves the device’s short-circuit safety and reverse recovery capability. In summary, the SAM-LIGBT achieves snapback-free operation and an excellent trade-off between the forward voltage drop $V_{\mathrm {ON}}$ and the turn-off loss $E_{\mathrm {OFF}}$ .