Au-induced lateral crystallization of a-Si1−xGex (x: 0-1) at low temperature

Au-induced lateral crystallization of amorphous Si1−xGex (x: 0-1) on SiO2 at a low temperature (400 °C) has been investigated. Although the growth velocity decreased with increasing Ge fraction, growth velocity exceeding 20 μm/h was obtained for all Ge fractions. As a result, poly-Si1−xGex with large areas (> 20 μm) was obtained at a low temperature (400 °C). This is a great advantage of Au-induced lateral crystallization compared with Ni. However, the concentrations in the surface regions (depth: 0-20 nm) of the lateral growth regions were high (10-30%), though those in the deeper regions (depth: 20-50 nm) were as small as 1-2%. Removing of the surface regions with the high Au concentrations and gettering of Au atoms in the deeper regions are necessary to apply the grown layers to the device fabrication.