AVS 45th International Symposium
    Surface Science Division Thursday Sessions
       Session SS-ThP

Paper SS-ThP2
Study of Aluminum Deposition on GaN (0001)@footnote 1@

Thursday, November 5, 1998, 5:30 pm, Room Hall A

Session: Surface Science Division Poster Session
Presenter: H. Cruguel, Montana State University
Authors: H. Cruguel, Montana State University
Y. Yang, Montana State University
S.H. Xu, Montana State University
G.J. Lapeyre, Montana State University
J.F. Schetzina, North Carolina State University
Correspondent: Click to Email
GaN has attracted much attention because of its great importance in fabricating light emitting diodes (LED), detectors and laser devices which operate in the green, blue and ultraviolet range. The vapor (in situ) deposition of Al on wurzite n-GaN(0001) clean surface is investigated with high-resolution photoemission. The samples grown at North Carolina State University were successfully clean by several techniques and measured at the Wisconsin Synchrotron Radiation Center (SRC).We have measured both Al 2p and Ga 3d photoemission level for different coverage of Al on GaN. With the Voigt line fitting of Al 2p we found two components, in addition to the metallic component, for all the deposition. The behavior is attributed to the formation of both AlGa@sub x@N@sub 1-x@ and AlN compounds on the GaN surface. The explanation is in agreement with the line fitting of Ga 3d level which also shows three components (bulk GaN, AlGa@sub x@N@sub 1-x@ and metallic). When we anneal the sample after the Al deposition the metallic peak disappears but the intensity of the two other components of the Al line and the components in the Ga line associate with AlGa@sub x@N@sub 1-x@ are still increasing. This means that the reaction still occurs and that the thickness of the two compounds increases. In addition we have deposited Mg on the sample to determine which compound is nearest the surface. We found that a metallic peak is only observed in Al 2p spectra. The results suggest that the sequence of materials is AlN on top, following by AlGa@sub x@N@sub 1-x@ and then GaN. The interpretation of the data will be presented. @FootnoteText@ @Footnote 1@ Research supported by ONR/DEPSCOR grant, SRC supported by NSF.