Investigation of Schottky Barrier on GaAs and InP Using a Multidisciplined Approach
Abstract
A major development this year was the Advanced Unified Defect Model (AUDM). This focus on the AsGa and the GaAs antisites as the key defect which can govern the electronic properties at GaAs/metal as well as other GaAs interfaces. One importance of this is that it provides a framework through which the interfacial chemistry can be related to changes in Schottky barrier height. Details of the AUDM and its development are given in paper 6 on our list of publications. A copy is attached to this report. The Fermi level position will be set by the relative number of AsGa and GaAs antisites. Because of the excess As and LEC GaAs, the AsGa antisites usually dominate when LEC crystals are used. Thus the Fermi level is pinning near midgap. If an interface reaction produces excess As, the Fermi level, Ef, moves toward the CVM; if excess Ga Ef moves toward the VBM. As can be seen from the Figure, good agreement is obtained with the careful experimental data generated under this contract in annealing experiments. However, it is important that this work be expanded to other metals. Oxides or other foreign layers at the interface complicate matters. However, it appears that the model appears even in these cases. The potential significance of this model goes far beyond the annealing experiments listed above. For example, it suggests that interfacial behavior may depend on the amount of As in the As grown crystals. Thus, we are initiating work on LEC crystals grown less As rich.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 20, 1988
- Accession Number
- ADA202953
Entities
People
- Al Green
- Nathan Newman
- William E. Spicer
Organizations
- Stanford University