Optical Studies of the Interface States at GaAs-Metal Schottky Barrier Junctions.
Abstract
The goal of the proposed research was to study surface states at GaAs metal Schottky barrier junctions and the effects of oxygen exposure on the surface states using both optical and electrical measurements with the goal of correlating the optical and electrical results. The correlation could not be achieved because the optical measurements were unsuccessful in detecting the surface states. From the electrical measurements, the following results were obtained: oxygen-exposure before the metallization with Al produces a large increase in the surface density of states peaking about 0.28 eV above the Fermi level; Al-GaAs diodes metallized without oxygen exposure had ideality factors of n equal to less than 1.1; Ag-GaAs diodes with oxygen exposure also show a surface state density peaking about 0.3 eV above the Fermi level. However, the surface state density is considerably lower than for oxygen-exposed AlGaAs diodes; Au-GaAs diodes with oxygen exposure show a surface state density which peaks about 0.45 eV above the Fermi level. Again, this density is considerably lower; from the above, oxygen at a GaAs-metal interface plays an important role in determining the surface state density. The theoretical part of this study to calculate electronic energies at GaAs surface was also unsuccessful. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1980
- Accession Number
- ADA083758
Entities
People
- Gerald P. Alldredge
- Ralph W. Alexander Jr.
- Robert J. Bell