L. Hart et al., MEASUREMENT OF INTERFACE ROUGHNESS IN A SUPERLATTICE OF DELTA-BARRIERS OF AL IN GAAS USING HIGH-RESOLUTION X-RAY-DIFFRACTOMETRY, Journal of physics. D, Applied physics, 28(4A), 1995, pp. 154-158
Aluminium delta-barriers grown in GaAs at 400 degrees C by molecular b
eam epitaxy have been studied using high-resolution x-ray diffractomet
ry. Superlattice structures of up to 100 periods enabled measurement o
f layers containing fractions of a monolayer of Al. It was also possib
le to determine the period variation and interface roughness or gradin
g to a depth resolution of about a monolayer by measuring the weak, hi
gh-order satellites around the 002 Bragg reflection. Dynamical simulat
ions showed that there was no interface roughness or grading beyond tw
o monolayers depth. The results were compared with those from Si delta
-doped GaAs, in order to provide an understanding of Si delta-doping,
which has a wide range of device applications.