AVS 49th International Symposium
    Electronic Materials and Devices Tuesday Sessions
       Session EL+SC-TuM

Paper EL+SC-TuM2
Structure of InAs/InP Interfaces Formed During Metalorganic Vapor-Phase Epitaxy

Tuesday, November 5, 2002, 8:40 am, Room C-107

Session: Heterojunctions
Presenter: D.C. Law, University of California, Los Angeles
Authors: D.C. Law, University of California, Los Angeles
Y. Sun, University of California, Los Angeles
C.H. Li, University of California, Los Angeles
S.B. Visbeck, Siemens & Shell Solar Gmbh
G. Chen, University of California, Los Angeles
R.F. Hicks, University of California, Los Angeles
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We have studied the initial stages of heterojunction formation during the metalorganic vapor-phase epitaxy of indium arsenide on indium phosphide. Exposing an InP (001) film to 10 mTorr of tertiarybutylarsine below 500 °C results in the deposition of a thin InAs layer from 1.5 to 5.0 atomic layers thick (2.3 to 7.5 Å). The surface of this epilayer remains atomically smooth independent of arsenic exposure time. However, in an overpressure of tertiarybutylarsine at or above 500 °C, the arsenic atoms diffuse into the bulk, creating strained InAsP films. These films form three-dimensional island structures to relieve the built-up strain. The arsenic transport into InP can be described by a constant-source diffusion model with the arsenic number density given by: N@subAs@ = 0.5 N@subT@erfc (x/2@sq@(D@subeff@t)). The activation energy and pre-exponential factor for arsenic diffusion into indium phosphide are: D@subo@ = 2.3±1.0 x10@super -7@ cm@super2@/s and E@subd@ = 1.7±0.2 eV.