M. El-gomati et al., A computer controlled chemical bevel etching apparatus: applications to Auger analysis of multi-layered structures, APPL SURF S, 145, 1999, pp. 128-131
Analysis of thin layer structures can be achieved by chemically etching a b
evel and subsequently analysing the surface. However non-linear bevels ofte
n result due to differing etch rates of the materials lending to incorrect
analysis results, We report on a computer controlled stepper motor reactor
whereby the specimen is lowered into the etchant at a rate which compensate
s for the different etch rates of the various layers constituting the sampl
e. The apparatus is used to produce linear bevels of various magnifications
on GaAs/AlGaAs heterostructures. The etchant of H3PO4/H2O2/H2O is used for
bevel preparation capped by a water layer to suppress the meniscus. Applic
ation of the technique to Multi Quantum Wells (MQW) and Bragg diffraction l
ayers is shown. The depth resolution of the bevelled samples are analysed b
y AES and a comparison is made to conventional ion sputtering techniques. (
C) 1999 Elsevier Science B.V. All rights reserved.