CMOS-compatible high-performance silicon photodetector by femtosecond-laser hyperdoping and nanosecond-laser annealing.

Femtosecond-laser hyperdoped silicon has emerged as a promising material for the preparation of photodetectors, because of its ultraviolet-near-infrared response spectrum that transcends the bandgap limitations of monocrystalline silicon, along with superior spectral responsivity at low bias and an exceptionally high dynamic range. However, the dependence on thermal annealing post-processing limits the consistency of femtosecond-laser hyperdoping with the trends toward low thermal budget and miniaturization in semiconductor fabrication. Developing high-performance hyperdoped silicon photodetectors compatible with complementary metal-oxide-semiconductor (CMOS) processes and other silicon-based device technologies has consistently been a considerable challenge. This work employed femtosecond-laser hyperdoping followed by nanosecond-laser annealing to fabricate sulfur-hyperdoped silicon. The resulting materials exhibit high-quality single-crystallinity and stable ultraviolet-near-infrared high-absorptance properties. The corresponding hyperdoped silicon photodetector demonstrates a peak responsivity of 117.62 A/W and a specific detectivity of 1.04 × 10 Jones at 900 nm which are the highest values reported for laser-annealed silicon-based photodetectors. This preparation process eliminates the reliance on thermal annealing for hyperdoping and addresses the compatibility issues between hyperdoping techniques and CMOS technologies. It provides a promising solution for high-performance ultraviolet-near-infrared CMOS devices, opening up what we believe to be new possibilities for advancing complex and miniaturized device designs.