T.J. De Lyon, J.A. Kash, et al.
Applied Physics Letters
We present the first direct measurement of proton energy-loss straggling in Ga1-xAlxAs/GaAs, enabling us to take maximum advantage of the 27Al (p, γ) 28Si nuclear reactions as a powerful nondestructive technique for measuring Al profiles in these structures. Results were obtained using samples produced by molecular beam epitaxy and fabricated to have step-function Al concentration distributions to prescribed depths. The exact straggling width was obtained by a least-square comparison of the experimental spectra with curves calculated using a parameterized straggling distribution. With these results, profiling measurements can now be made giving the Al concentration fall-off at the GaAl/GaAs interface with a spatial depth resolution of about 4% and epilayer thickness determinations to about 2%. We have also observed in one sample a nonabrupt transition at the GaAlAs/GaAs interface, due to differences in substrate surface preparation procedures prior to growth of the GaAlAs layer.
T.J. De Lyon, J.A. Kash, et al.
Applied Physics Letters
A. Bond, P. Parayanthal, et al.
Cambridge Symposium 1983
X. Yin, X. Guo, et al.
Applied Surface Science
X. Yin, H.-M. Chen, et al.
Applied Physics Letters