Metal-induced lateral crystallization (MILC) of amorphous Ge has been investigated to realize low temperature formation of poly-Ge films on insulating substrates. From a comparative study of MILC with various catalysis metals (Ni, Co, Pd, and Cu), it was found that Cu enhanced both nucleation and subsequent nucleus growth the most significantly among the species. Consequently, low temperature (similar to 250 degrees C) growth with a high velocity (similar to 1 mu m/h) of poly-Ge films becomes possible by employing Cu as the catalyst. This technique will accelerate the realization of advanced high-speed TFT on flexible substrates. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3582794] All rights reserved.