Published online by Cambridge University Press: 26 February 2011
We have examined various methods of overcoming the problems of low growth efficiency and high carbon uptake which occur when GaAs is grown at low temperatures by Metal Organic Molecular Beam Epitaxy (MOMBE). We have found that removal of the carbon through conventional means such as precracking or interaction with hydrogen is not effective in enhancing the carbon removal process. In fact, the use of a hydrogen plasma during growth actually increases the carbon background due to a reduction in the surface V/III ratio. Greater success is obtained when alternative precursors are used as replacements for AsH3 and triethylgallium (TEG). Tris-dimethylaminoarsenic (DMAAs) offers reduced carbon uptake through formation of amine compounds while tri-isobutylgallium (TTBG) shows better efficiency and less carbon than TEG at low growth temperature.