AVS 52nd International Symposium
    Surface Science Tuesday Sessions
       Session SS1-TuA

Paper SS1-TuA6
Phosphine and Tertiarybutylphosphine Adsorption on the Indium-Rich InP (001)-(2x4) Surface

Tuesday, November 1, 2005, 3:40 pm, Room 202

Session: Compound Semiconductors
Presenter: R.L. Woo, University of California, Los Angeles
Authors: R.L. Woo, University of California, Los Angeles
S.F. Cheng, University of California, Los Angeles
G. Chen, University of California, Los Angeles
Y. Sun, University of California, Los Angeles
R.F. Hicks, University of California, Los Angeles
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Phosphine (PH3) and tertiarybutylphosphine (TBP) are widely used as the group V sources during the MOCVD growth of P-containing compound semiconductors and their alloys. The kinetics of PH3 and TBP adsorption and phosphorus desorption from InP (001) have been studied using optical techniques and reflectance difference spectroscopy. It is found that the sticking probability of TBP decreases from 0.007 to 0.001 with increasing temperature from 420 to 520 ËsC; whereas the sticking probability of PH3 is approximately equal to 0.001 over the same range. In this report, we present a vibrational study of TBP and PH3 adsorption on the indium-rich InP (001)-(2x4) surface. Both molecules form a dative bond to exposed indium atoms on the surface. A fraction of these species decompose to PH2 or PH species with hydrogen and tertiarybutyl ligands transfering to nearby phosphorus sites. The initial datively bonded state explains the low sticking probability of these molecules, as reversible desorption competes effectively with irreversible dissociative adsorption at elevated temperatures.