The use of helium ion RBS for profiling epitaxial layers of CdxHg1−xTe

Abstract This paper describes the application of helium ion RBS and channelling to the characterization of an epitaxial layer of Cd x Hg 1 − x Te. The layer was grown by MOVPE on a substrate of GaAs as part of a programme for developing infrared detector materials. The use of RBS with the aid of computer techniques is discussed for obtaining compositional ( x ) profiles both within the layers and, in particular, in the near-surface region. Conventional- and grazing-geometry measurements have been used to establish layer quality and interfacial abruptness. Variations in composition close to the surface have been correlated with the conditions under which layer growth was terminated. Channelling measurements are presented for the assessment of the layer crystalline quality.