Processing issues for wafer bonded III-V on insulator structures

InP template layers were bonded and transferred by hydrogen implantation onto GaAs handle wafers to create a III-V semiconductor on insulator type structure. This structure is then used to determine the crystalline quality of the hydrogen split template layers for III-V applications. High resolution X-ray diffraction, double crystal X-ray topography, and transmission electron microscopy are employed in this study to investigate the structural defects in these wafer bonded III-V on insulator structures. Additionally, processes that may lead to improved crystallinity of the transferred layers, such as thermal annealing and chemical mechanical polishing, are explored. Hydrogen split InP layers were found to exhibit a higher degree of crystalline damage throughout the layer as compared to bond and etch back transferred layers. This is attributed to bonding non-uniformities and possibly ion implantation damage. No improvement in the crystalline quality is observed by subsequent annealing up to 1000 °C. However, a chemical mechanical polishing step using a NaOCl and citric acid slurry is found to improve the surface quality of the transferred layer without inducing additional crystalline damage.