Semiconductor processing with excimer lasers

The advantages of pulsed excimer lasers for semiconductor processing are reviewed. Extensive comparisions of the quality of annealilng of ion‐implanted Si obtained with XeCl and ruby lasers have been made. The results indicate that irrespective of the large differences in the optical properties of Si and UV and visible wave‐lengths, the efficienccy of usage of the incident energy for annealing is comparable for the two lasers. However, because of the excellent optical beam quality, the XeCl lasser can provide superior control of the surface melting and the resulting junction depth. Furthermore, the concentrations of electrically active point defects in the XeCl laser annealed region are 2−3 orders of magnitude lower than that obtained from ruby or Nd:YAG lasers. All these results seem to suggest that XeCl lasers should be suitable for fabricating not only solar cells but also the more advanced device structures required for VLSI or VHSIC applications.