Low-temperature (less than or equal to550 degreesC) Ni-mediated crystallization of amorphous SiGe (a-Si1-xGex (0 less than or equal to x less than or equal to 1)) layers on SiO2 films has been investigated. The morphology of crystallized SiGe strongly depended on the Ge fraction. For low Ge fractions (<20%), Ge-doping enhanced plane growth was observed, which resulted in strain-free poly-Si0.8Ge0.2 films with large grains (18 mum). On the other hand, dendrite growth was dominant for intermediate Ge fractions (40-60%). Directions and widths of dendrites became straight and narrow with decreasing annealing temperature. Very sharp needle-like crystals (width: 0.05 mum, length: 10 mum) were obtained at the optimized growth conditions (Ge fraction: 40%, annealing: 450 degreesC, 20 h). These new poly-SiGe films on insulator should be utilized for the advanced system-in-displays and novel devices such as one-dimensional quantum wires. (C) 2003 Elsevier B.V. All rights reserved.