Abstract
Ex situ nonalloyed ohmic contacts were made to n- and p-type GaAs using low-temperature molecular beam epitaxy. For n-type GaAs, Ag, and Ti/Au nonalloyed contacts displayed specific contact resistitivities of mid 10−7 Ω cm2. For p-type GaAs, nonalloyed Ti/Au contacts with specific contact resistivities of about 10−7 Ω cm2 were obtained.
Highlights
Department of Electrical and Computer EngineeringFollow this and additional works at: https://docs.lib.purdue.edu/ecepubs Part of the Electrical and Computer Engineering Commons
Alloyed ohmic contacts have been used extensively for GaAs devices
For Si-doped, n-type GaAs, the bulk doping density is limited to NDϪNA Ϸ5ϫ1018 cmϪ3
Summary
Follow this and additional works at: https://docs.lib.purdue.edu/ecepubs Part of the Electrical and Computer Engineering Commons. During molecular beam epitaxyMBEof Si-doped, n-GaAs, very high values of NDϪNA Such a layer should facilitate nonalloyed ohmic contacts, but the native oxide that forms and the subsequent oxide etch that is done prior to metal evaporation removes most of this high space charge density layer at the surface. We describe a new technique that passivates the high space charge density layer on the surface of MBE n-GaAs with a layer of LTG GaAs thereby permitting ex situ nonalloyed ohmic contacts with a c of mid 10Ϫ7 ⍀ cm[2]. We describe a LTG and a subsequent anneal that drives interstitial Be onto acceptor sites giving a higher p-type doping, giving a lower c, and improving the film’s stability
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
