Dynamics of the excimer laser annealing of hydrogenated amorphous silicon thin films

Time-resolved reflectivity and time-resolved conductivity spectroscopies ha ve been used to monitor phase changes as a function of pulse-energy density during the recrystallization of amorphous hydrogenated Si by an ArF excime r laser. The simultaneous application of both spectroscopies allowed clear identification of the melting threshold and time of melting. The dc conduct ivity of irradiated Si was measured as a function of pulse energy and numbe r of pulses. These results, together with Raman spectroscopy, revealed that single-pulse annealing gives a conductive, but still amorphous and rather defective layer. At least two consecutive pulses are necessary for obtainin g of the substantial crystalline fraction. (C) 1999 American Institute of P hysics. [S0003-6951(99)01930-0].