New high-power BIMOS-devices based on silicon-silicon bonding

This paper investigates the feasibility of using silicon-silicon bonding technology for combined bipolar-MOSFET-devices (BIMOS) such as MOS-turn-off thyristors (MTO). With the help of this new bonding technique several power MOSFETs are connected to a bipolar disc-type device structure. The MOSFET dies are used to switch the BIMOS-device. At the same time, the reverse conducting diode of the MOSFETs operates as a pn-junction of the classical thyristor structure during on-state. The proposed technology accomplishes the fabrication of BIMOS-devices without bonding wires, which are used in state-of-the-art MTO and ETO devices. Device operation similar to a fully integrated structure can be achieved without the technological problems in manufacturing VLSI-structures on large disc-type devices. In this paper, different MTO type device topologies based on the proposed idea are presented and compared by finite element simulation results.