PREPARATION OF SI1-XGEX THIN CRYSTALLINE FILMS BY PULSED EXCIMER-LASER ANNEALING OF HEAVILY GE IMPLANTED SI

Thin crystalline Si1-xGex layers were obtained by irradiating heavily Ge implanted (10(17) atoms cm-2) [100] oriented Si substrates with a p ulsed excimer (ArF) laser. The respective influences of the implantati on conditions, laser energy density or number of successive laser puls es were investigated using Rutherford backscattering channeling analys is and Raman spectroscopy. In particular, it is shown that layers of g ood crystalline quality can be readily obtained, the width almost cons tant Ge concentration being controlled by the irradiation conditions. Optimizing these conditions leads to 200 nm thick alloy layers with a constant Ge content x = 0.14. These results were interpreted using a c omputer simulation based on the melting-resolidification process which occur during the pulsed laser irradiations.