A study on the leakage current of poly-Si TFTs fabricated by metal inducedlateral crystallization

Leakage current of poly-Si TFT fabricated by a metal induced lateral crysta llization(MILC) process was investigated in terms of metal contamination an d crystallization mechanisms. MILC poly-Si TFTs showed a higher leakage cur rent than those by the solid phase crystallization method at high drain vol tages. It turned out that the Ni rich phases in the depleted junction regio n played the role of trapping and recombination centers to generate the lea kage currents and that the leakage current was generated by thermionic fiel d emission. The leakage current could be drastically reduced to 5 pA/mu m a t V-GS = 0 V and V-DS = 15 V after the exclusion of the Ni-rich phase from the junction region by a Ni offset MILC process. (C) 1999 Elsevier Science Ltd. All rights reserved.