Metal-induced solid-phase crystallization of amorphous SiGe films on insulator

The metal-induced low-temperature (less than or equal to550degreesC) crystallization of a-Si1-xGex (0 less than or equal to x less than or equal to 1) on SiO2 has been investigated. A Ge-fraction-dependent crystal growth was observed. In the case of a low-Ge fraction, plane growth dominated, the velocity of which was enhanced by 80% with increasing Ge fraction from 0 to 20%. This produced strain-free poly-SiGe with large grains (18mum). On the other hand, dendrite growth became dominant in the case of intermediate Ge fractions (40-60%). By optimizing the growth conditions (x: 0.4, annealing: 450degreesC, 20 h), very sharp needlelike crystals (width: 0.05mum, length: 10mum) were obtained. These new polycrystalline SiGe films on insulator should be used for system-in-display, three-dimensional ultra large-scall integrated circuits, and novel one-dimensional wires.