Low-temperature dopant activation and its application to polycrystalline silicon thin film transistors

Low-temperature activation of dopants in amorphous silicon films was achieved by a new method and high-performance polycrystalline silicon thin film transistors were fabricated through its application. It was found that the dopants implanted into amorphous silicon were activated simultaneously with the crystallization of amorphous silicon. With the help of a thin nickel layer, the thermal budget for dopant activation and crystallization was considerably reduced, from 600 degrees C (30 h) to 500 degrees C (5 h). Even without plasma hydrogenation, the n-channel polycrystalline silicon thin film transistors fabricated at temperatures below 500 degrees C showed a mobility of 120 cm(2)/V s, which is much higher than that of conventional devices fabricated at 600 degrees C. (C) 1996 American Institute of Physics.