Gac. Jones et al., IN-SITU SCANNING TUNNELING MICROSCOPE STUDIES OF HIGH-ENERGY, FOCUSEDION-IMPLANTATION OF GA INTO GAAS - DIRECT OBSERVATION OF ION-BEAM PROFILES, Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, 16(4), 1998, pp. 2570-2573
The profile of an ion beam line exposure of Ga+ ions into GaAs(100) wa
s characterized in situ using scanning probe microscopy. Current imagi
ng tunneling spectroscopy was used to characterize the surface defects
induced by the high-energy Ga+ ions. Spatially reproducible features,
approximately one per ion and 2-3 nm in diameter, were observed on th
e irradiated surface. Differential conductance spectra of these featur
es indicated that the image contrast was due to acceptor states induce
d in the surface band gap. The density of these defects was used to fo
rm a profile of the ion beam in the semiconductor surface. The resulti
ng profile was in excellent agreement with the two-Gaussian fit report
ed in previous work. (C) 1998 American Vacuum Society.