XPS study of Au/GaN and Pt/GaN contacts
R. Sporken, C. Silien, F. Malengreau, K. Grigorov, R. Caudano
Facultés Universitaires Notre-Dame de la Paix , Belgium
F. J. Sánchez, E. Calleja, E. Muñoz
Dpt. Ingeniería Electrónica, E.T.S.I. Telecomunicación, Politécnica, Ciudad Universitaria
B. Beaumont, Pierre Gibart
Centre de Recherche sur l'Hetero-Epitaxie et ses Applications, CRHEA-CNRS
This article was received on June 10, 1997 and
accepted on September 4, 1997. Abstract
Au/GaN and Pt/GaN contacts have been studied with XPS.
According to XPS depth profiling, the N signal is weak in the region below the
metal contact and the Pt or Au signal decreases much more slowly than expected
for a sharp interface. Next, we have performed in situ studies of the formation
of Au contacts on GaN. In contrast to the results from depth profiling, we
observe 2D growth and little or no chemical interaction between Au and GaN.
This suggests that conventional calculations of sputtering yields and
ion-beam-induced mixing cannot be applied to the analysis of noble metal/GaN
depth profiles. Heating during or after Au deposition results in strong
clustering, observed by both XPS and AFM. The Schottky barrier height measured
by XPS is 1.15 eV.
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Cite this article as: MRS Internet J. Nitride Semicond. Res. 2, 23(1997).
last updated October 15, 1997 5:05:23 PM.© 1997 The Materials Research Society
