TiB_2 and ZrB_2 diffusion barriers in GaAs Ohmic contact technology
Abstract
The transition metal diboride compounds, ZrB_2 and TiB_2, interposed between Ni/Ge/Au Ohmic contact metallization on n‐type GaAs wafers and an overlying thick Au contact layer, have been investigated to evaluate their effectiveness in stabilizing the Ohmic contact by limiting the in‐diffusion of Au. All of the metal layers were e‐beam deposited except the ZrB_2 which was rf‐diode sputtered. The barrier layer thicknesses were 50 and 100 nm for the TiB_2 and the ZrB_2, respectively. Postdeposition alloying of the contacts was performed at 400, 425, or 450 °C. Auger electron spectroscopy depth profiling of the resultant Ohmic contacts demonstrates that the barrier layers effectively preclude penetration of Au to the Ohmic contact structure. Specific contact resistivities for such contacts are in the low 10^(−7) Ω cm^2 range; although some degradation of the contact resistivity is observed after long term annealing, the values of resistivities do not exceed 1.5×10^(−6) Ω cm^2 after 92 h at 350 °C.
Additional Information
© 1985 American Vacuum Society. Received 10 May 1985; accepted 17 June 1985. The cooperation of M. Wade, D. Eckart, L. Heath, D. Troy, and T. AuCoin is appreciated.Attached Files
Published - SHAjvsta85.pdf
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Additional details
- Alternative title
- TiB2 and ZrB2 diffusion barriers in GaAs Ohmic contact technology
- Eprint ID
- 32159
- Resolver ID
- CaltechAUTHORS:20120627-153155843
- Created
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2012-06-27Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field