Room-temperature bonding of GaAs//Si and GaN//GaAs wafers with low electrical resistance

The electrical properties of room-temperature bonded wafers made from materials with different lattice constants, such as p-GaAs and n-Si, p-GaAs and n-Si [both with an indium tin oxide (ITO) surface layer], and n-GaN and p-GaAs, were investigated. The bonded p-GaAs//n-Si sample exhibited an electrical interface resistance of 2.8 x 10(-1) Omega.cm(2) and showed ohmic-like characteristics. In contrast, the bonded p-GaAs/ITO//ITO/n-Si sample showed Schottky-like characteristics. The bonded n-GaN//p-GaAs wafer sample exhibited ohmic-like characteristics with an interface resistance of 2.7 Omega.cm(2). To our knowledge, this is the first reported instance of a bonded GaN//GaAs wafer with a low electrical resistance. (C) 2018 The Japan Society of Applied Physics