Formation of Periodic Diffraction Structures at Semiconductor Surfaces for Studying the Dynamics of Photoinduced Phase Transitions

摘要

New methods for the formation of measuring periodic diffraction structures at silicon surfaces are proposed and tested. The one-dimensional grating is formed at a surface of implanted silicon by nanosecond laser annealing in the regime of interference of two crossed beams. The two-dimensional grating is formed at the surface of single-crystal silicon by implantation through a special periodic mask. Diffraction gratings formed are amplitude gratings because their periodically alternating fragments differ only in the reflection coefficient. The amplitude gratings were transformed into phase gratings by irradiation by pulses of incoherent light in the regime of local melting. A noticeable increase in the diffraction efficiency is found in this case, which allows these gratings to be used to study the dynamics of various phase transitions induced by high-power incoherent light pulses in implanted silicon.