Accession Number:

ADA591293

Title:

Effect of as Passivation on Vapor-Phase Epitaxial Growth of Ge on (211)Si as a Buffer Layer for CdTe Epitaxy

Descriptive Note:

Journal article

Corporate Author:

ARMY RESEARCH LAB ADELPHI MD

Report Date:

2011-04-07

Pagination or Media Count:

8.0

Abstract:

We report an investigation of epitaxial germanium grown by chemical vapor deposition CVD on arsenic-terminated 211Si, which is the preferred substrate in the USA for fabrication of night-vision devices based on mercury cadmium telluride MCT grown by molecular-beam epitaxy MBE. The films were characterized by scanning electron microscopy SEM, atomic force microscopy AFM, cross-sectional transmission electron microscopy XTEM, and x-ray diffraction XRD. Arsenic passivation was found to be effective in preventing cross-contamination of unwanted residual species present inside the reactor chamber and also in prolonging the evolution of layer-by-layer growth of Ge for significantly more monolayers than on nonpassivated Si. The two-dimensional 2D to three-dimensional 3D transition resulted in Ge islands, the density and morphology of which showed a clear distinction between passivated and nonpassivated 211Si. Finally, thick Ge layers 250 nm were grown at 525 C and 675 C with and without As passivation, where the layers grown with As passivation resulted in higher crystal quality and smooth surface morphology.

Subject Categories:

  • Inorganic Chemistry
  • Physical Chemistry
  • Metallurgy and Metallography
  • Crystallography
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE