Presentation on theme: "SURFACE TRANSFORMATIONS AND GROWTH OF NANOCRYSTALS ON Au-COVERED GaAs and InP CRYSTALS Prof. Dr. Imre MOJZES MINAEST-NET TU Berlin/FhG-IZM, Berlin, Germany."— Presentation transcript:
SURFACE TRANSFORMATIONS AND GROWTH OF NANOCRYSTALS ON Au-COVERED GaAs and InP CRYSTALS Prof. Dr. Imre MOJZES MINAEST-NET TU Berlin/FhG-IZM, Berlin, Germany 22 April 2005
Participants Imre Mojzes A, Sándor Kökényesi B, István A. Szabó C, Istvan Ivan B, Béla Pécz D A – Budapest University of Technology and Economics, Department of Electronics Technology H-1111 Budapest Goldmann Gy. ter 3. B – Debrecen University, Department of Experimental Physics H-4026 Debrecen, Bem ter 18/a Hungary C - Debrecen University, Department of Solid State Physics H-4010 Debrecen POB 2 Hungary D – Institute of Technical Physics and Material Sciences of the Hungarian Academy of Sciences
Abstract We present a simple method of nanocrystal growth during the heating of Au-covered GaAs single crystals in a closed quartz ampoule. The process is the final stage of surface transformations in such crystals which include the disruption of initially continuous, 50 nm thick Au-layer and formation of Au-particle fractals in the relatively low o C temperature range and a next step, when a variety of crystalline nanowires and even nanotubes grows on the crystal surface during the further short-period heating up to o C. These nanostructures were indentified by SEM and TEM measurements as -Ga 2 O 3 and a nonstoichiometric arsenic oxide. It is supposed that the growth of few nanometer thick arsenic oxide tubes follows the vapour-solid mechanism, whereas the catalytic Au-metal growth of thicker -Ga 2 O 3 nanowires was dominated by the vapor-liquid-solid mechanism.
Roots Interaction of gold based contacts with compound semiconductors GaAs, InP, InAs, GaSb, InSb, GaP.. InGaAlAs, GaAsP GaAs microwave semiconductor devices
Experimental n – GaAs - 50nm Au HEATING quartz ampoule (10 -3 torr, H 2 O, saturated As 2 ) in SEM (high pumping rate) GaAs, InP