Characterization of LPE Grown HgCdTe by Ion Scattering Spectrometry.
Abstract
Results are shown here for low energy ion scattering spectrometry (ISS) experiments on mercury cadmium telluride (HCT) grown by liquid phase epitaxy (LPE) on CdTe substrates. By proper etching of the substrates and control of epitaxial growth conditions, surfaces of the zinc blend structure may be obtained in which 111 faces have a top layer of cadmium and mercury (A sites) or of tellurium (B sites). Ion scattering experiments at low energies (500 V or less) on epitaxial HCT show only A or B sites. However, when the helium or neon ion beam potenntial is raised to values conventionally used (1500-2500 V), then energy losses from both A and B atoms are observed. At these higher energies the ions sputter or displace the outer atoms or tunnel through to interact with atoms in the second layer. Spectra obtained at these higher energies show interesting fine structure which suggest that energy losses are occurring in multiple collisions and nonbinary scattering. Scattered ion yield curves, which for some elements, show oscillatory fine structure, are dramatically different for A and B surfaces. Even though these yield curves are very complicated because of the structure and number of elements, the fine structure may prove useful for further understanding of interaction of neighboring atoms. Yield curves along with low energy ion scattering spectra provide a unique method of analysis of the outermost atomic layer of epitaxial films.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1979
- Accession Number
- ADA077884
Entities
People
- W. L. Baun
Organizations
- Air Force Research Laboratory