Gf. Mclane et al., MAGNETRON ENHANCED REACTIVE ION ETCHING OF GAAS IN CH4 H2/AR - SURFACE DAMAGE STUDY/, Journal of vacuum science & technology. A. Vacuum, surfaces, and films, 12(4), 1994, pp. 1356-1359
Citations number
18
Categorie Soggetti
Physics, Applied","Materials Science, Coatings & Films
An investigation was performed of surface region etch-induced damage o
f GaAs magnetron reactive ion etched in CH4/H-2/Ar gas mixtures. Trans
mission electron microscope measurements revealed the presence of etch
-induced defects which extended 4.3, 7.2, and 8.7 nm below the surface
for Ar concentrations of 0%, 10%, and 20%, respectively, in the gas m
ixture. Auger electron spectroscopy measurements showed that etching p
roduced an As-deficient surface region extending approximately 10 nm b
elow the surface. The amount of As deficiency increased with Ar concen
tration, but was relatively unaffected by postetch annealing at 400-de
grees-C for 30 s. Changes in Schottky barrier surface potential PHI(b)
upon etching and subsequent annealing can be explained by a combinati
on of H passivation effects and As removal from the surface, whereas c
hanges in Schottky barrier diode ideality factor n can be explained by
the presence of etch-induced surface region defects such as donorlike
As vacancies and deep level recombination centers, both of which are
passivated by H.