Chemical, electrical, and structural properties of Au/Pd contacts on chemical vapor cleaned p-type GaN surfaces

P. J. Hartlieb, A. Roskowski, B. J. Rodriguez, Robert Nemanich, R. F. Davis

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The chemical, electrical, and microstructural properties of Au/Pd contacts on p-type GaN(0001) surfaces previously cleaned either ex situ or ex situ and in situ have been investigated. The in situ process involved a high temperature, NH 3-based chemical vapor clean (CVC); it produced ordered, stoichiometric, p-type GaN surfaces with no detectable C and an O constituent which was subsequently reduced from 15 at% on the ex situ treated surface to 2 ± 1 at% following the CVC process. The Pd contacting layer grew epitaxially in a layer-by-layer mode on the CVC surface and formed an abrupt, unreacted metal-semiconductor interface. The Au capping layer also grew epitaxially on the Pd. Au/Pd contacts on both HCl and CVC treated surfaces exhibited identical surface roughness values (RMS) in the as-deposited state and following a 500°C anneal. Contact structures on CVC treated surfaces demonstrated excellent high-temperature microstructural stability as evidenced by the absence of significant change in the surface roughness (RMS) with successive annealing at 600 and 700°C. Identical contact structures on ex situ cleaned surfaces exhibited poor high temperature microstructural stability, as indicated by a significant increase in the surface roughness (RMS) following successive anneals at 600 and 700°C. There was a significant degradation in the morphology of both surfaces following the 800°C anneal as evidenced by the formation of large voids in the contact metallization and the exposure of the underlying p-type GaN substrate. The lowest resistance contact structures with uniform metal coverage were obtained for Au/Pd contacts on a CVC treated surface annealed at 700°C.

Original languageEnglish (US)
Title of host publicationMaterials Research Society Symposium - Proceedings
EditorsJ.E. Northrup, J. Neugebauer, D.C. Look, S.F. Chichibu, H. Riechert
Pages737-742
Number of pages6
Volume693
StatePublished - 2002
Externally publishedYes
EventGaN and Related Alloys-2001 - Boston, MA, United States
Duration: Nov 26 2001Nov 30 2001

Other

OtherGaN and Related Alloys-2001
CountryUnited States
CityBoston, MA
Period11/26/0111/30/01

Fingerprint

Contacts (fluid mechanics)
Chemical properties
Structural properties
Electric properties
Vapors
Surface roughness
Metals
Contact resistance
Metallizing
Temperature
Annealing
Semiconductor materials
Degradation
Substrates

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

Hartlieb, P. J., Roskowski, A., Rodriguez, B. J., Nemanich, R., & Davis, R. F. (2002). Chemical, electrical, and structural properties of Au/Pd contacts on chemical vapor cleaned p-type GaN surfaces. In J. E. Northrup, J. Neugebauer, D. C. Look, S. F. Chichibu, & H. Riechert (Eds.), Materials Research Society Symposium - Proceedings (Vol. 693, pp. 737-742)

Chemical, electrical, and structural properties of Au/Pd contacts on chemical vapor cleaned p-type GaN surfaces. / Hartlieb, P. J.; Roskowski, A.; Rodriguez, B. J.; Nemanich, Robert; Davis, R. F.

Materials Research Society Symposium - Proceedings. ed. / J.E. Northrup; J. Neugebauer; D.C. Look; S.F. Chichibu; H. Riechert. Vol. 693 2002. p. 737-742.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Hartlieb, PJ, Roskowski, A, Rodriguez, BJ, Nemanich, R & Davis, RF 2002, Chemical, electrical, and structural properties of Au/Pd contacts on chemical vapor cleaned p-type GaN surfaces. in JE Northrup, J Neugebauer, DC Look, SF Chichibu & H Riechert (eds), Materials Research Society Symposium - Proceedings. vol. 693, pp. 737-742, GaN and Related Alloys-2001, Boston, MA, United States, 11/26/01.
Hartlieb PJ, Roskowski A, Rodriguez BJ, Nemanich R, Davis RF. Chemical, electrical, and structural properties of Au/Pd contacts on chemical vapor cleaned p-type GaN surfaces. In Northrup JE, Neugebauer J, Look DC, Chichibu SF, Riechert H, editors, Materials Research Society Symposium - Proceedings. Vol. 693. 2002. p. 737-742
Hartlieb, P. J. ; Roskowski, A. ; Rodriguez, B. J. ; Nemanich, Robert ; Davis, R. F. / Chemical, electrical, and structural properties of Au/Pd contacts on chemical vapor cleaned p-type GaN surfaces. Materials Research Society Symposium - Proceedings. editor / J.E. Northrup ; J. Neugebauer ; D.C. Look ; S.F. Chichibu ; H. Riechert. Vol. 693 2002. pp. 737-742
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abstract = "The chemical, electrical, and microstructural properties of Au/Pd contacts on p-type GaN(0001) surfaces previously cleaned either ex situ or ex situ and in situ have been investigated. The in situ process involved a high temperature, NH 3-based chemical vapor clean (CVC); it produced ordered, stoichiometric, p-type GaN surfaces with no detectable C and an O constituent which was subsequently reduced from 15 at{\%} on the ex situ treated surface to 2 ± 1 at{\%} following the CVC process. The Pd contacting layer grew epitaxially in a layer-by-layer mode on the CVC surface and formed an abrupt, unreacted metal-semiconductor interface. The Au capping layer also grew epitaxially on the Pd. Au/Pd contacts on both HCl and CVC treated surfaces exhibited identical surface roughness values (RMS) in the as-deposited state and following a 500°C anneal. Contact structures on CVC treated surfaces demonstrated excellent high-temperature microstructural stability as evidenced by the absence of significant change in the surface roughness (RMS) with successive annealing at 600 and 700°C. Identical contact structures on ex situ cleaned surfaces exhibited poor high temperature microstructural stability, as indicated by a significant increase in the surface roughness (RMS) following successive anneals at 600 and 700°C. There was a significant degradation in the morphology of both surfaces following the 800°C anneal as evidenced by the formation of large voids in the contact metallization and the exposure of the underlying p-type GaN substrate. The lowest resistance contact structures with uniform metal coverage were obtained for Au/Pd contacts on a CVC treated surface annealed at 700°C.",
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