Structure And Reliability Metal Contacts to GaAs.
Abstract
These results make it clear that any change in near-interfacial stoichiometry, e.g., by reaction of the metal overlayer with the substrate, will result in a change in barrier height and thus a change in the electrical performance of the device. Using electrical and microstructural characterization, we have investigated a wide range of metal/GaAs systems including the metals Ti, Al, Cr, Pd and Au. The Fermi level pinning position is found to relate directly to the amount of excess As near the interface: very As- rich GaAs results in pinning near midgap and thus a low barrier height for n- GaAs; less As-rich conditions result in pinning closer to the valence band and thus a high barrier height for n-GaAs. The observation was made by comparing near-interfacial stoichiometry of different metals with low and high barrier height, and by studying the change in near-interfacial stoichiometry upon annealing.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 1991
- Accession Number
- ADA259184
Entities
People
- Eicke R. Weber
- Jack Washburn
Organizations
- University of California, Berkeley