PROCESS EFFECTS IN SHALLOW JUNCTION FORMATION BY PLASMA DOPING

We have characterized the effect of implant parameters on the characte ristics of boron-implanted silicon prepared by plasma doping. The thic kness of the amorphous layer was monitored using Rutherford backscatte ring spectrometry, transmission electron microscopy, and double crysta l x-ray diffraction. At low plasma implant pulse biases (2 kV), both d ose rate and pulse repetition rate (10 Hz to 1 kHz) were found to have a negligible effect on the generation of the surface amorphous layer. At higher voltages (5 kV), the thickness of the amorphous layer incre ased with the pulse repetition rate but was apparently not sensitive t o the dose rate. The sheet resistance after annealing correlated stron gly with the increasing thickness of the surface amorphous layer forme d at 5 kV. From these results, we conclude that an increase in pulse r epetition rate has a stronger effect on the formation of the surface a morphous layer than does dose rate. (C) 1998 American Vacuum Society.