Giant replicate cell approach to the electronic structure calculation of graded interface regions
The usual approach to the theory of interfacial electron states is to assume that the interfaces join abruptly. A multilayer slab geometry is then elected for the calculation of electronic states using methods of varying degree of sophistication. In many cases, the interfaces between semiconductors or dielectric insulators may involve a transition region of several atomic layers. The electron states at one side of the transition region may be quite different from those of the other side. The artificial abrupt connection of the two faces in this case will result in a great strain of bonds at the interface and could lead to the identification of unrealistic interfacial states. An alternate approach to this problem is proposed. We construct a series of giant periodic cells with atomic coordination commensurate with the bonding configurations of the interfacial region. A microscopic first-principles electronic structure calculation is then applied to each giant cell which replicates the bulk interfacial region. Information such as density of states, partial density of states, gap states, and electron localization can be obtained and correlated to the atomic structures. Results for density of states are presented for SiO/sub x/ with x = 1.5, 1.0, and 0.5 as would be appropriate for the Si--SiO/sub 2/ interfacial region. States at the upper region of the valence band are found to consist of mainly Si orbitals and their degree of localization is proportional to x. Application of this method to other compound semiconductor interfaces is also discussed.
- Research Organization:
- Department of Physics, University of Missouri-Kansas City, Kansas City, Missouri 64110
- DOE Contract Number:
- AC02-79ER10462
- OSTI ID:
- 5068672
- Journal Information:
- J. Vac. Sci. Technol.; (United States), Vol. 21:2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Controlling the defects and transition layer in SiO2 films grown on 4H-SiC via direct plasma-assisted oxidation
Challenges in Nanoelectronics - Gate Dielectrics and Device Modeling (invited)
Related Subjects
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
SEMICONDUCTOR MATERIALS
ELECTRONIC STRUCTURE
ENERGY-LEVEL DENSITY
SILICON OXIDES
ENERGY LEVELS
INTERFACES
VALENCE
CHALCOGENIDES
MATERIALS
OXIDES
OXYGEN COMPOUNDS
SILICON COMPOUNDS
360603* - Materials- Properties
656000 - Condensed Matter Physics