Two-beam laser recrystallization of polycrystalline silicon on an insulating substrate

A novel two-laser technique has been investigated for recrystallizing polycrystalline silicon deposited on an insulating substrate. An Ar+ laser and a CO2 laser have been scanned simultaneously to perform the recrystallization of unpatterned samples and samples patterned with antireflection stripes. The use of the two beams enabled recrystallization without the use of a substrate heater, and resulted in grain widths a factor of 2 larger than those obtained with the more conventional technique using an Ar+ laser only. A Raman microprobe analysis revealed that the stress in the two-beam recrystallized material was about an order of magnitude less than found in Ar+ laser recrystallized material. The polarization dependence of the Raman scattered light indicated that the orientation of the recrystallized material between antireflection stripes was in a 〈100〉 orientation.