PHOTOLUMINESCENCE STUDY OF IMPLANTATION DOSE AND DOSE-RATE DEPENDENCEOF SI DOPING OF GAAS

Photoluminescence spectroscopy is used to investigate some of the rece ntly reported effects of implantation dose and dose rate on the electr ical activation of Si dopant in GaAs. Two new luminescence bands are o bserved to emerge in our spectra with the increasing Si dose at doses (similar to 2x10(13) cm(-2)) where the carrier concentration is known to saturate. The higher energy band at the similar to 840-880 nm wavel ength shows a more pronounced rise in strength with increase in dose r ate from 3 nA/cm(2) beam current density to 60 nA/cm(2). The deep-leve l luminescence band extending from similar to 1000 to similar to 1600 nm wavelength dominates the spectra for both the low-dose-rate and cm( -2). The observed rapid generation of type-I high-dose-rate samples ab ove a dose of similar to 2x10(13) cm(-2). The observed rapid generatio n of type-I dislocations above this dose suggests this band is related to some impurity Cottrell atmospheres around the dislocations in GaAs . (C) 1997 American Institute of Physics.