High temperature wafer bonding technique for the realization of a voltage and current bidirectional IGBT

For applications requiring voltage and current bidirectional switches like the matrix converter application, the bidirectional switch can be obtained by associating unidirectional switches. However, this arrangement leads to an increase of the on-state voltage drop and increases the circuit complexity. In order to overcome these drawbacks, it is necessary to design a monolithically integrated MOS controlled current and voltage bidirectional switch. This paper focuses on the monolithically integrated bidirectional IGBT. This well known structure consists of MOS sections on each side of the wafer. The difficulty with this structure mainly resides in its realization and control. This paper is an attempt to demonstrate the feasibility of a bidirectional IGBT using a double side photolithography technique on one hand and proposes a high temperature bonding technique that could be used for the realization of a bidirectional IGBT using the Si/Si wafer bonding technique on the other hand.