Growth of Silicon Carbide Nanowires by a Microwave Heating-Assisted Physical Vapor Transport Using Group VIII Metal Catalysts

Published

November 13, 2007

Author(s)

Siddarth Sundaresan, Albert Davydov, Mark D. Vaudin, Igor Levin, James E. Maslar, Yong-lai Tian, M V. Rao

Abstract

SiC nanowires are grown by a novel catalyst-assisted sublimation-sandwich (SS) method. This involves microwave heating-assisted physical vapor transport from a source 4H-SiC wafer to a closely positioned substrate 4H-SiC wafer. The substrate wafer is coated with a group VIII (Fe, Ni, Pd, Pt) metal catalyst film about 5 nm thick. The nanowire growth is performed in a nitrogen atmosphere, in the temperature range of 1650 C to 1750 C for 40 s durations. The nanowires grow by the vapor-liquid-solid (VLS) mechanism facilitated by metal catalyst islands that form on the substrate wafer surface at the growth temperatures used in this work. The nanowires are 10 m to 30 m long. About 52% of the nanowires had diameters in the range of 15 nm 150 nm, whereas 14% of the nanowires had diameters in excess of 300 nm. Electron backscatter diffraction (EBSD) and selected area electron diffraction (SAD) analyses confirmed nanowires to crystallize with a cubic 3C structure of 3C-SiC. EBSD from the nanowire caps were indexed as Fe2Si, Ni3Si, Pd2Si, and PtSi phases for the nanowires grown using Fe, Ni, Pd, and Pt as the metal catalysts, respectively. The nanowires are found to grow along the 112 directions, as opposed to the commonly observed 111 directions. The -Raman spectra from single nanowires indicate regions with varying compressive strain in the nanowires and also shows modes not arising from the Brillouin zone-center, which may indicate the presence of defects in the nanowire.

Citation

Chemistry of Materials

Volume

19

Issue

23

Pub Type

Journals

Keywords

catalyst, growth, microwave, nanovires, SiC

Citation

Sundaresan, S. , Davydov, A. , Vaudin, M. , Levin, I. , Maslar, J. , Tian, Y. and Rao, M. (2007), Growth of Silicon Carbide Nanowires by a Microwave Heating-Assisted Physical Vapor Transport Using Group VIII Metal Catalysts, Chemistry of Materials (Accessed December 4, 2024)