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Title: Ohmic contacts to plasma etched n-Al{sub 0.58}Ga{sub 0.42}N

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.2357867· OSTI ID:20860932
; ; ; ;  [1]
  1. Department of Materials Science and Engineering, Pennsylvania State University, and the Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

Plasma etching is required to expose n-Al{sub x}Ga{sub 1-x}N layers for bottom-emitting ultraviolet light emitting diodes grown on sapphire. However, etching can increase the difficulty of forming Ohmic contacts. X-ray photoelectron spectroscopy and cathodoluminescence reveal how the semiconductor changes with etching and help explain why it becomes more difficult to form an Ohmic contact. A V/Al/V/Au metallization has been investigated for Ohmic contacts to n-Al{sub 0.58}Ga{sub 0.42}N etched with a BCl{sub 3}/Cl{sub 2}/Ar chemistry. Increased V thickness and higher annealing temperatures were required to obtain a specific contact resistance of 4.7x10{sup -4} {omega} cm{sup 2} for etched n-Al{sub 0.58}Ga{sub 0.42}N compared to optimized contacts on unetched films.

OSTI ID:
20860932
Journal Information:
Applied Physics Letters, Vol. 89, Issue 13; Other Information: DOI: 10.1063/1.2357867; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English