Homoepitaxial Mosaic Growth and Liftoff of Diamond Films

Growth of large area, single or almost single crystal diamond is of great importance to the electronics industry. In this work, single crystal diamonds were implanted with C+ ions, inducing a subsurface damage layer in the diamond lattice. Homoepitiaxial diamond films were then grown on the implanted crystals using a microwave plasma CVD reactor. Films grown on on-axis substrates were dominated by large numbers of hillocks, renucleation and penetration twins, while miscut substrates exhibited stepflow growth. The homoepitaxial layers were separated from the substrate by a water-based etch which selectively attacks the subsurface damage layer of the diamond lattice. The films were analyzed by Raman scattering, scanning electron microscopy (SEM), optical microscopy, photo- and cathodoluminescence, and x-ray diffraction. CVD growth on adjacent, oriented substrates formed a single, continuous diamond layer. The resulting homoepitaxial film quality, orientation, defect density and it’s relationship to the underlying substrates were compared at various points on the surface, particularly the region which overgrew the gap between different substrates.