Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 13: Quantum Dots and Wires: Preparation and Characterization I

HL 13.13: Vortrag

Montag, 22. März 2010, 17:15–17:30, H17

Epitaxial silicon nanowire growth catalyzed by gold dot arrays from electron beam lithography patterning using silane precursors — •Björn Hoffmann, Gerald Brönstrup, Uwe Hübner, and Silke Christiansen — Institut für Photonische Technologien e.V., Abt. Halbleiter Nanostrukturen, 07745 Jena

Ordered arrays of silicon nanowires (SiNWs) are promising building blocks for a variety of photonic, photovoltaic and sensor applications. In our approach to create SiNWs we use electron beam lithography (EBL) and thermal metal evaporation to create nano-patterned arrays of gold nanodots on a Si(111) wafer. These Au dots are subsequently used to catalyze the bottom-up growth of SiNWs that follow the vapor-liquid-solid (VLS) growth mechanism using silane in a CVD reactor.

The grown nanowires are characterized structurally using SEM, TEM and electron backscatter diffraction (EBSD).

We observe epitaxial growth of the SiNWs on the Si(111) wafer and we are able to control the growth direction to be either dominated by <111> or <112> directions by just changing the silane partial pressure. The lengths as well as the diameters of the wires are precisely controlled by the EBL Au dot patterning and CVD parameters. To predict wire diameters modelling is carried out that takes into account the EBL- and CVD-parameters and describes the observed experimental results very well.

Furthermore we were able to create single crystalline Au-dot arrays which are very promising structures for surface enhanced raman spectroscopy (SERS) substrates.