About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Publication
Physical Review B
Paper
Atomic-scale composition fluctuations in III-V semiconductor alloys
Abstract
Composition fluctuations in epitaxially grown III-V compound semiconductor alloys are observed with atomic resolution in direct space. A tunneling microscope technique is employed on the (110) cross-sectional plane of epitaxially grown InGaAsP-InP and AlGaAs-GaAs multilayers cleaved in ultrahigh vacuum. The tunneling polarity is used to image the filled-state group-V (As,P) sublattice in InGaAsP and the empty-state group-III (Al,Ga) sublattice in AlGaAs. In both compounds, the atomic-scale variations observed in the charge density reflect the composition fluctuations in the respective sublattices: an attempt is made to identify different elements of similar valence (Al,Ga). The definition of the heterojunction interface can be directly assessed on the atomic scale. © 1993 The American Physical Society.