Interface Structures of III-V Semiconductor Heterostructures

Abstract

We report first-principles calculations of the electronic and geometric structure of the (110) cross-sectional surfaces on InAs/GaSb superlattices and compare the results to scanning tunneling microscopy images of filled electronic states. We also study the atomic scale structure of (001) interface surfaces and the adsorption of deposited atoms on these surfaces to simulate the process occurring during the heterostructure growth. In both the predicted and measured images the InAs (110) surfaces appear lower than GaSb, a height difference we show is caused primarily by differences in the electronic structure of the two materials. In contrast, local variations in the apparent height of (110) surface atoms at InSb- or GaAs-like interfaces arise primarily from geometric distortions associated with local differences in bond length. We further observed that both Ga- and Sb-terminating (001) surfaces showed dimerization of surface atoms. Ga-terminating (001) surfaces exhibited substantial buckling of surface atoms while Sb-terminating (001) surfaces did not show appreciable buckling. The adsorption of arsenic atoms occurred preferably at the bridge sites between the dimerized Sb atoms on Sb-terminating (001) surfaces. Indium atoms, on the other hand, were observed to have somewhat equal probabilities to be adsorbed at a few different sites on Ga-terminating (001) surfaces. Our calculated energies for atomic intermixing indicate that anion exchanges are exothermic for As atoms on Ga-terminating (001) interfaces but endothermic for In atoms on Sb-terminating (001) interfaces. This difference may explain why GaAs interfaces are typically more disordered than InSb interfaces in these heterostructures.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2003
Accession Number
ADA482562

Entities

People

  • B. Z. Nosho
  • Jun Shen
  • Lloyd J. Whitman
  • S. C. Erwin
  • Seong-gon Kim
  • Sungho Kim

Organizations

  • Mississippi State University

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms

DTIC Thesaurus Topics

  • Adsorption
  • Buckling
  • Chemistry
  • Computational Science
  • Contrast
  • Crystal Lattices
  • Crystal Structure
  • Crystals
  • Density Functional Theory
  • Electronic Structure Methods
  • Energy Bands
  • Epitaxial Growth
  • Field Effect Transistors
  • Materials
  • Quantum Chemistry
  • Semiconductors
  • Superlattices

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Organic Chemistry
  • Quantum Dot Semiconductor Device Photonics and Graphene Optoelectronic Materials and THz Physics.

Technology Areas

  • Microelectronics
  • Microelectronics - Graphene