AVS 49th International Symposium
    Electronic Materials and Devices Wednesday Sessions
       Session EL+SS+SC-WeA

Paper EL+SS+SC-WeA2
Structure-Sensitive Oxidation of the Indium Phosphide (001) Surface

Wednesday, November 6, 2002, 2:20 pm, Room C-107

Session: Semiconductor Film Growth and Oxidation
Presenter: G. Chen, University of California, Los Angeles
Authors: G. Chen, University of California, Los Angeles
S.B. Visbeck, Siemens & Shell Solar Gmbh, Germany
D.C. Law, University of California, Los Angeles
R.F. Hicks, University of California, Los Angeles; AVS fellow
Correspondent: Click to Email
Abstract The properties of oxide/semiconductor interfaces significantly affect the performance of indium phosphide-based electronic and photonic devices. In this study, indium phosphide films were grown on InP (001) substrates by metalorganic chemical vapor deposition (MOCVD). Then the samples were transferred to an ultrahigh vacuum system, and annealed at 623 and 723 K to produce the (2x1) and delta(2x4) reconstructions with phosphorus coverages of 1.0 and 0.125 ML, respectively. These structures were exposed to unexcited molecular oxygen, and the reaction characterized by X-ray photoelectron spectroscopy (XPS), reflectance difference spectroscopy (RDS) and low energy electron diffraction (LEED). At 298 K and above, the In-rich InP (001) surface rapidly oxidizes upon exposure to O2. The oxygen dissociatively chemisorbs onto the delta (2x4), inserting into the In-P back bonds and the In-In dimer bonds. By contrast, the P-rich (2x1) reconstruction does not absorb O2 up to 500,000 L at 298 K. Above 453 K, the (2x1) becomes reactive with oxygen inserting into both the In-P back bonds and the phosphorus dimer bonds. Based on these results, we conclude that the oxidation of indium phosphide (001) is highly structure sensitive. This means that the oxide/semiconductor interface formed on InP devices can vary widely depending on the process history.