Manufacture of silicon-based devices having disordered sulfur-doped surface layers

A method of fabricating a semiconductor structure, comprising

• irradiating a plurality of locations on a surface of a silicon substrate with one or more laser pulses having pulse widths in a range of about 50 to about 500 femtoseconds while exposing said surface to a substance having an electron-donating constituent so as to generate a micro-structured surface layer comprising inclusions incorporating said electron-donating constituent, and
• annealing said substrate at an elevated temperature in a range of about 500 K to about 1100 K for a selected time period.

A method of fabricating a radiation-absorbing semiconductor wafer, comprising:

• irradiating at least one surface location of a silicon substrate with a plurality of temporally short laser pulses while exposing said location to a substance having an electron-donating constituent so as to generate a substantially disordered surface layer incorporating a concentration of said electron-donating constituent, and
• annealing said substrate at an elevated temperature and for a duration selected to enhance charge carrier density in said substantially disordered surface layer.

A method of enhancing responsivity of a radiation-absorbing semiconductor wafer to incident radiation, comprising

• irradiating at least one surface location of a silicon substrate with temporally short laser pulses while exposing the substrate to a substance having an electron-donating constituent so as to generate a microstructured surface layer having inclusions containing the electron-donating constituent, and
• annealing the substrate at an elevated temperature and for a duration selected to enhance a responsivity of the microstructured substrate to radiation having at least one wavelength in a range of about 250 nm to about 1100 nm incident on the microstructured surface layer by at least a factor of about 10.