Disruption, Atom Distributions, and Energy Levels for Ge/GaAs(110),Ge/InP(110), and Ge/InSb(110) Heterojunctions. (Reannouncement with New Availability Information).

摘要

Interfaces have come under increased scrutiny, in part because they exhibit unique structural, electronic, and chemical properties. For semiconductor heterojunctions, the fact that the two semiconductors have different energy gaps results in valence and conduction-band discontinuities. In turn, these offsets play a crucial role in the electrical properties of the heterojunction, and they can be used in the design of solid-state electronic devices. Despite significant advances of the past few years, many fundamental questions remain. Most theoretical treatments of heterojunction band lineups have assumed abrupt, lattice-matched interfaces. Likewise, most assume that there is an absolute energy associated with each semiconductor so that the band offsets reflect differences in those energies. Experimentally, however, it has been observed that the electrical properties can be related to the chemical and geometric structure at the interface and can be dictated by deviations from perfection. In particular, band offsets can depend on such variables as substrate orientation, overlayer crystallinity, the order of deposition, and interdiffusion or reactivity. In such cases, there is no unique value for the lineup and experiments must therefore provide better insight into structure-property correlations for heterojunctions.