Semiconductor processing with excimer lasers

Abstract

The advantages of pulsed excimer lasers for semiconductor processing are reviewed. Extensive comparisions of the quality of annealing 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 at UV and visible wavelengths, the efficiency of usage of the incident energy for annealing is comparable for the two lasers. However, because of the excellent optical beam quality, the XeCl laser 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.

Recent Advances in Thin Film Electronic Devices

“…It is found that laser treatment can improve the crystallinity of ZnO materials, and the mobility of TFT devices is increased by more than 2.5 times (0.19 to 0.49 cm 2 /Vs) as shown in Figure 8 [58]. There is usually a certain energy threshold in metal oxide thin films, and the laser energy exceeding the threshold will induce the recrystallization or grain growth of the thin films [68,78,79]. The grain size usually increases with the increase of laser energy density [80,81].…”

Application of Laser Treatment in MOS-TFT Active Layer Prepared by Solution Method

“…When the laser energy density increases to 130 mJ/cm 2 , the performance of the device decreases, as shown in Figure 7 [75]. There is usually a certain energy threshold in metal oxide thin films, and the laser energy exceeding the threshold will induce the recrystallization or grain growth of the thin films [68,78,79]. The grain size usually increases with the increase of laser energy density [80,81].…”

Performance improvements of IGZO and ZnO thin‐film transistors by laser‐irradiation treatment

“…In addition, the effectiveness of pulsed laser annealing in removing lattice damage and restoring crystalline order has already been reported. 17 Laser irradiation treatment thus plays an important role in determining the crystal structure of these films.…”