TEM/HREM of Ti/Al and WNi/Ti/Al ohmic contacts for n-AlGaN

Author

Ruvimov, S. ; Liliental-Weber, Z. ; Washburn, J. ; Qiao, D. ; Lui, Q.Z. ; Lau, S.S.

Author_Institution

Lawrence Berkeley Lab., CA, USA

fYear

1998

fDate

1998

Firstpage

247

Lastpage

250

Abstract

High resolution and analytical transmission electron microscopy was applied to characterize the microstructure of Al/Ti and W/Al/Ti ohmic contacts to AlGaN/GaN HFET structures. Formation of a 15-25 nm thick interfacial AlTi₂N layer appears to be essential for ohmic contract behavior indicating a tunneling contact mechanism. Contact resistance was found to depend on the structure and composition of the metal and AlGaN layers, and on atomic structure of the interface. Contact resistivity increases with Al fraction in the AlGaN layer

Keywords

III-V semiconductors; aluminium; aluminium compounds; contact resistance; field effect transistors; gallium compounds; interface structure; nickel alloys; ohmic contacts; semiconductor-metal boundaries; titanium; transmission electron microscopy; tungsten alloys; tunnelling; Al fraction; HFET; HREM; TEM; WNi-Ti-Al-AlGaN; contact resistance; interface atomic structure; interfacial AlTi₂N layer; microstructure; ohmic contacts; tunneling contact mechanism; Aluminum gallium nitride; Contact resistance; Contracts; Gallium nitride; HEMTs; MODFETs; Microstructure; Ohmic contacts; Transmission electron microscopy; Tunneling;

fLanguage

English

Publisher

ieee

Conference_Titel

Semiconducting and Insulating Materials, 1998. (SIMC-X) Proceedings of the 10th Conference on

Conference_Location

Berkeley, CA

Print_ISBN

0-7803-4354-9

Type

conf

DOI

10.1109/SIM.1998.785117

Filename

785117