Atomically Accurate Structure Analysis for InAs/InAsSb StrainedLayer Superlattices STIR
Abstract
We use cross-sectional STM to effectively discriminate between arsenic and antimony sites in mixed groupV semiconductor alloys grown by MBE. Our effort is directed toward two problems representing distinctly different facets of a common material system: InAsSb. Project1, undertaken jointly with Sandia National Laboratories, assesses the difference between the asgrown and intended [001] antimony profile in an InAs / InAsSb strainedlayer superlattice arising from antimony segregation and cross-incorporation. We show how the STM data fully explain the observed HRXRD spectrum and predict a corresponding strain profile that may also be tested against TEM. Project 2,undertaken jointly with the Army Research Laboratory, addresses the anion sublattice order in a bulk, metamorphic InAsSb alloy. We demonstrate how crosssectional STM permits a semi-quantitative assessment of shortrange order by way of an imagebased antimonyantimony correlation function reconstructed from largearea STM surveys. Project 1 has a direct impact on the predicted band structure and carrier transport in MWIR strainedlayer superlattices, whereas Project 2 potentially bears on the orderinginduced bandgap anomaly in LWIR bulk alloys.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 30, 2015
- Accession Number
- AD1001453
Entities
People
- Michael B. Weimer
Organizations
- Texas A&M University