MOVPE growth of Ga(AsBi)/GaAs using different metalorganic precursors

• MOVPE growth of high quality Ga(AsBi) layers with alternative Bi- and Ga-precursors
• A strong room temperature PL signal for all three Bi precursors
• Growth of GaAs with TTBGa there is even an one order of magnitude lower C incorporation ascompared to the growth with TEGa
• effect of hydrocarbon groups from the metal organic precursor decomposition
• TTBGa, TIPBi and TTBBi are promising candidates for the growth of Ga(AsBi), at even lower growth temperatures

In this paper different metalorganic Bismuth- and Gallium-precursors such as Triisopropylbismuth, Tritertiarybutylbismuth, Trimethylbismuth, Triethylgallium and Tritertiarybutylgallium, were investigated to grow Ga(AsBi) by metal organic vapour phase epitaxy (MOVPE). Use of different precursors which dissociate at different temperatures and have various decomposition pathways can lead to an understanding of the complex growth chemistry at low temperatures, possibly enabling the growth of Ga(AsBi) at very low growth temperatures in order to further increase the Bi fraction. The growth conditions were varied over a wide range in order to investigate the Bi-incorporation and growth rate comprehensively. Using different methods like high resolution X-ray diffraction, scanning electron microscopy and secondary ion mass spectroscopy, we found that especially in the low temperature regime not only the decomposition of the precursors is important but also the interaction between the different molecules and processes at the surface, like surface coverage and pyrolysis of the precursors, needs to be taken into account. Furthermore, it is demonstrated that the growth of Ga(AsBi) with the novel precursors is possible and results in high quality Ga(AsBi) samples.