Scanning tunneling microscopy of point defects and interfaces in compound semiconductors

Journal Article · Tue Aug 01 04:00:00 EDT 1995 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.48809· OSTI ID:279570

Zheng, J F; Salmeron, M; Weber, E R ^[1]

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1. Materials Science Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)

We have used Scanning Tunneling Microscopy (STM) to study dopants, point defects, and interfaces in compound semiconductors after cleavage in Ultra-High-Vacuum. Features due to Si{sub Ga} donors and Zn{sub Ga} acceptors in the STM images of n{sup +} GaAs and p{sup +} GaAs have been identified and characterized on an atomic scale. For the first time, we found the spherical and triangle-shape delocalized Si{sub Ga} donor and Zn{sub Ga} acceptor features, respectively. In heavily doped n{sup +} GaAs, Ga vacancies were observed that produce characteristic dark delocalized spherical features. The Ga vacancies tend to locate close to Si{sub Ga} donors. We imaged an antisite defect in n{sup +} GaAs. High resolution STM spectroscopic images revealed very rich detail of the electronic structures of that site. Isoelectronic In and Ga elements in In{sub 0.2}Ga{sub 0.8} alloy were also identified. This allowed us to investigate the interfaces of GaAs/In{sub 0.2}Ga{sub 0.8}As/GaAs strained layer quantum wells atom-by-atom. Segregation of In at the In{sub 0.2}Ga{sub 0.8}As/GaAs interface and clustering inside In{sub 0.2}Ga{sub 0.8}As were studied.

• Research Organization: Lawrence Berkeley National Laboratory
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 279570
• Report Number(s): CONF-9409150--
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 342; ISSN 0094-243X; ISSN APCPCS
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ACCEPTORS
DONORS
ELECTRON MICROSCOPY
ELECTRONIC STRUCTURE
GALLIUM ARSENIDES
INDIUM ALLOYS
INTERFACE STRUCTURE
POINT DEFECTS
SEMICONDUCTOR MATERIALS
SILICON
STM
VACANCIES
ZINC