Dopant activation and crystal recovery in arsenic-implanted ultra-thin silicon-on-insulator structures using 308nm nanosecond laser annealing

The different regimes encountered when submitting ultra-thin SOI structures implanted with arsenic to single pulse laser annealing with increasing energy density, are identified. It is found that nanosecond UV laser annealing can be successfully applied to rebuild a perfect monocrystalline SOI layer and reach arsenic activation levels at least as high as rapid thermal processing, with a reasonably large process window. Thanks to electrical and morphological characterizations, the defective or polycrystalline silicon obtained below the optimum range is evidenced, as well as the loss of monocrystalline nature of the silicon at the upper end of the process window.