Ml. Wise et al., DETECTION OF SPUTTERED NEUTRALS BY ULTRAHIGH-INTENSITY POSTIONIZATIONIN THE NEAR-INFRARED, Analytical chemistry, 67(22), 1995, pp. 4033-4039
Characterization of sputtered semiconductor materials by ultrahigh-int
ensity postionization has been performed utilizing a high repetition r
ate, regeneratively amplified, ultrafast Ti-sapphire laser coupled wit
h a modified magnetic-sector SIMS instrument. The laser produces 120-f
s pulses with focused intensities well in excess of 10(14) W/cm(2) at
800 nm and 1 kHz, Studies of common matrices such as GaAs, InP, InGaAs
P, and SiO2 indicate that both singly and multiply charged ions as wel
l as molecular ions can be detected with high efficiency in both surfa
ce analysis and depth-profiling sputtering modes. Relative sensitivity
factors for the different elements are determined and related to the
photoionization mechanism and to the other factors that can affect the
detection efficiency. Future directions for such a technique are disc
ussed.