From confocal overgrowth to lateral growth of InAs nanostructures on Si substrates by MOVPE
by Kamil Sladek, Fabian Haas, Markus Heidelmann, Daesung Park, Juri Barthel, Falk Dorn, Thomas Weirich, Detlev Grützmacher, and Hilde Hardtdegen
STEM measurements performed with the PICO microscope have been used to develop a methodology for the deposition of lateral InAs nanostructures on silicon by selective area metal organic vapour phase epitaxy (SA-MOVPE). Growth parameters which are optimal for the SA-MOVPE of conformal InAs overgrowth on GaAs nanowires were transferred to the lateral SA growth of InAs structures on patterned silicon substrates. The substrate pretreatment conditions and growth parameters were further optimised with respect to selectivity and nanostructure morphology. It is found that lateral growth of InAs nanostructures can be achieved on patterned Si(110) as well as on patterned silicon on insulator (SOI) substrates. An investigation of the laterally grown InAs/Si nanowires' crystal structure revealed a faceted but nevertheless abrupt Si-InAs interface on the Si(110) substrate as well as relaxation and a high crystallinity of the deposited InAs on both Si template types. The morphology and crystallinity of laterally grown structures are discussed in detail and compared to that of vertical shell/core InAs/GaAs nanowires.
Kamil Sladek, Fabian Haas, Markus Heidelmann, Daesung Park, Juri Barthel, Falk Dorn, Thomas Weirich, Detlev Grützmacher, and Hilde Hardtdegen: From confocal overgrowth to lateral growth of InAs nanostructures on Si substrates by MOVPE, Journal of Crystal Growth 370 (2013) 141-145.