Demonstration of a GaAs-based compliant substrate using wafer bonding and substrate removal techniques

A GaAs-based compliant substrate that uses an intermediate AlGaAs-oxide layer to separate thin 150 /spl Aring/-1000 A GaAs compliant layers from a GaAs host substrate is described. The compliant substrates and epitaxial layers of lattice-mismatched In/sub 0.15/Ga/sub 0.85/As were studied using atomic force microscopy and double-crystal X-ray diffraction. The surface morphology of the 1000 A compliant substrate prior to growth had an RMS and peak-to-peak roughness of 10 /spl Aring/ and 100 /spl Aring/. Following growth of 3000 /spl Aring/ In/sub 0.15/Ga/sub 0.85/ the root mean square (RMS) roughness increased to 50 /spl Aring/, and slip lines were observed in the [110] direction. A comparison of lattice-matched p/sup +/-n junction diodes grown on a substrate with a 1000 /spl Aring/ compliant layer and a standard GaAs substrate revealed similar dark current-voltage characteristics, which demonstrate the high quality of the compliant substrate.