Study of Si-wafer directly bonded interface effect on power device characteristics

A high voltage transistor and an Insulated Gate Bipolar Transistor (IGBT) were fabricated by using Silicon-wafer Direct Bonding (SDB) technique to study the effect of direct bonded interface on power device characteristics. Prior to the device fabrication, heat treatment condition of SDB was investigated, and it was confirmed that electrically and mechanically stable SDB interface was obtaind at more than 1000°C. The transistor showed sufficiently high h^FE(=10) for this high voltage transistor. The fall-time and on-state voltage of IGBT were controlled by adjusting bonded interface position. All of these results encourage new SDB technique applications for power device improvements.