Published online by Cambridge University Press: 21 March 2011
Si/GaAs heterostructures were obtained by a low temperature direct wafer bonding (DWB) method which uses spin-on glass (SOG) intermediate layers. The use of intermediate SOG layers allows the fabrication of Si/GaAs heterostructures at processing temperatures lower than 200°C. The achieved bonding energy permits thinning down to a few microns of Si and GaAs wafers, respectively, using grinding procedures followed by chemical mechanical polishing (CMP). After thinning, the heterostructures sustained annealing temperatures of 450°C without damaging of the bonded interface. The above bonding procedure was successfully applied for bonding GaAs wafers to Si wafers with structured surfaces. A technology was developed based on this bonding method for producing universal GaAs-on-Si or Si-on-GaAs substrates.