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
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