Accession Number : ADA259184


Title :   Structure And Reliability Metal Contacts to GaAs.


Descriptive Note : Final rept. 1Jun 1986-31 Dec 1991,


Corporate Author : CALIFORNIA UNIV BERKELEY DEPT OF MATERIALS SCIENCE AND MINERAL ENGINEERING


Personal Author(s) : Weber, Eicke R ; Washburn, Jack


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a259184.pdf


Report Date : 31 Dec 1991


Pagination or Media Count : 43


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.


Descriptors :   *GALLIUM ARSENIDES , *METAL CONTACTS , METALS , STRUCTURES , RELIABILITY , MICROSTRUCTURE


Subject Categories : Physical Chemistry
      Electrical and Electronic Equipment


Distribution Statement : APPROVED FOR PUBLIC RELEASE