Metalorganic vapor-phase epitaxy of indium phosphide and related materials

The surface chemistry of indium phosphide and related compound semiconductors during metalorganic vapor-phase epitaxy (MOVPE) has been investigated. In particular, the group V precursor chemistry, indium phosphide (001) atomic structure and the InP oxidation process have been examined. The properties of the semiconductors were studied using infrared spectroscopy, molecular cluster calculations, x-ray photoelectron spectroscopy, reflectance difference spectroscopy, x-ray diffraction, and photoluminescence spectroscopy.; Indium phosphide, gallium arsenide phosphide, and aluminum indium phosphide have been deposited by MOVPE using tertiarybutylphosphine and tertiarybutylarsine. Minimum incorporation in InP was observed at 565°C and a V/III ratio of 32. In this case, the material contained a background carrier concentration of 2.7 x 1014 cm-3, and the Hall mobilities were 4,970 and 135,000 cm2/V·s at 300 and 77 K. The oxygen contamination in AlInP was found to be only 9.0 x 10 15 cm-3 for deposition at 650°C and a V/III ratio of 35. The relative distribution of arsenic to phosphorus in GaAs yP1-y was determined at temperatures between 525 and 575°C. The distribution coefficient [(NAs/ NP)film/(PTBAs /PTBP)gas] ranged from 25.4 to 8.4, and exhibited an Arrhenius relationship with an apparent activation energy of 1.2 eV.; The surface structure of the indium phosphide (001)-(2 x 1) reconstruction has been clarified in this thesis. Infrared spectra collected during atomic deuterium titration of the (2 x 1) surface revealed a sharp P-H stretching mode at 2308 cm-1. Based on theoretical cluster calculations using density functional theory, this mode was due to a single hydrogen atom bonded to one end of a buckled phosphorus dimer. These results confirmed that the (2 x 1) structure was stabilized by hydrogen.; Indium phosphide oxidation has been found to be an activated process and strongly structure sensitive. The In-rich (2 x 4) surface reacted with oxygen at 300 K and above. X-ray photoemission spectra revealed that the O 2 dissociatively chemisorbed onto the (2 x 4), inserting into the In-In dimer and In-P back bonds. By contrast, the P-rich (2 x 1) reconstruction did not absorb oxygen up to 5 x 105 L at 300 K. Above 455 K, oxygen reacted with the (2 x 1) inserting preferentially into the In-P back bonds and to a lesser extent into the phosphorus dimer bonds.