Stress-induced anomalous growth in lateral solid-phase epitaxy of Ge-incorporated Si films

Lateral solid-phase epitaxy (LSPE) characteristics of Ge-incorporated amorphous Si films which are deposited on SiO2Si (100) structures with [010] seed openings are investigated. It has been found in P-doped amorphous Si films that the LSPE growth rate at 600 °C is enhanced about sixfold by incorporation of 0.5 at.% Ge atoms, and that the maximum growth length is about 21 μm. It has also been found that the growth in the film with 1 at.% Ge atoms stops for a few hours upon annealing at temperatures lower than 600 °C at a length of about 2 μm from the seed edge and it proceeds again as annealing time is extended. To clarify the origin of the anomalous growth rate, the residual stress in the films has been measured using microprobe Raman spectrometry, and it is concluded that the origin of the enhanced growth is the residual stress in the films. Finally, it is suggested that the Ge-incorporated stress effect may be explained by the critical thickness theory in pseudomorphic growth of Si1-xGex films on Si substrates.