Improved diamond surfaces following lift-off and plasma treatments as observed by x-ray absorption spectroscopy

We have investigated the nature of the residual damage in diamond crystals following the ion implantation/graphitization “lift-off” process, using near-edge x-ray absorption fine structure spectroscopy and transmission electron microscopy. A defective but crystalline interface is found, which displays dense pre-edge unoccupied states and an almost complete loss of the core-level C 1s exciton signature. This residual crystalline damage is resistant to standard chemical etching, however a hydrogen plasma treatment is found to completely recover a pristine diamond surface. Analysis and removal of residual ion-induced damage is considered crucial to the performance of many diamond device architectures.