Nucleation-controlled metal-induced lateral crystallization of amorphous Si_1-xGe_x with whole Ge fraction on insulator

The effects of Ge fraction and annealing temperature on the metal-induced lateral crystallization (MILC) of amorphous SiGe films on an insulator have been investigated. It was shown that the progress of the MILC of amorphous SiGe was suppressed by spontaneous nucleation, which was accelerated with increases in Ge fraction and annealing temperature. Thus, MILC could not proceed for amorphous SiGe with high Ge fractions (>70%) at high temperatures (>500 °C). Spontaneous nucleation was significantly suppressed by lowering the annealing temperature (<400°C). As a result, the MILC of amorphous SiGe was achieved for samples with whole Ge fractions (0-100%), and large polycrystalline silicon-germanium (poly-SiGe) regions (>20μm) could be realized for even high Ge fractions (>70%). Transmission electron microscopy suggested that the mechanism of MILC of amorphous SiGe (a-SiGe) with medium and high Ge fractions (>40%) is different from that of a-Si.