Cathodoluminescence characterization of b-SiC nanowires and surface-related silicon dioxide F. Fabbri a,Ã , A. Cavallini a , G. Attolini b , F. Rossi b , G. Salviati b , B. Dierre c , N. Fukata d , T. Sekiguchi c a Phods Lab, Department of Physics, University of Bologna, CNISM, Viale Berti Pichat 6/2, 40127 Bologna, Italy b IMEM-CNR Institute, Viale Usberti 37/A, 43100 Parma, Italy c Nano Device Characterization Group, Advanced Electronic Materials Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan d International Center for Materials Nanoarchitectonics (MANA) and PRESTO JST, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan article info Available online 29 November 2008 PACS: 78.67.LT 78.66.DB 78.60.HK 78.30.AM Keywords: Silicon carbide Nanowire Cathodoluminescence Silicon dioxide abstract The main goal of our study is to prepare and to understand the properties of cubic SiC nanowires (NWs) and to characterize its native silicon dioxide. The wires, with diameters ranging from 10 nm to 2 mm, have been prepared by a CVD process on Si (0 0 1) substrates, using CO as the carbon source and Ni as the catalyst. A structural and optical analysis, by means of TEM, micro-Raman and cathodoluminescence (CL) spectroscopy, has been performed. Two sets of samples have been studied, labelled A and B, which differ for growth process conditions. Set A showed two broad CL peaks. Set B showed a much weaker CL emission. This difference has been explained by means of TEM investigation and micro-Raman spectra: set A shows a thick amorphous silicon dioxide layer on the wire surface, whereas set B shows a thin or absent oxide layer. Consequently, the nature of the CL emission has to be ascribed mainly to oxide-related recombination. & 2008 Elsevier Ltd. All rights reserved. 1. Introduction Silicon carbide (SiC) is an important wide band-gap semiconductor with superior properties, such as high breakdown field strength, high thermal conductivity, high saturation drift velocity, and excellent physical and chemical stability [1]. The applications of SiC cover the area of high-temperature sensors, high-power devices, and microwave devices. SiC has also demonstrated a superior biocompatibility with organic and biological systems [2]. In addition, the miniaturization of SiC devices is a fast trend for both industrial manufacturing and academic research. The combination of the distinctive physical and chemical properties of SiC and unique advantages of nanowires (NW) make SiC NWs an excellent candidate for designing and fabricating nanodevices. SiC NWs are also intensively investigated due to the forma- tion of native silicon dioxide shell. This effect allows the development of cylindrical nano-field effect transistor (NFET) with exceptional electrical properties [3]. 2. Experimental The growth of SiC NWs was performed in an open-tube by a carbothermal method based on the reaction between carbon monoxide and the native oxide on the (10 0) Si substrate, using nickel nitrate as the catalyst. At the growth temperature (1050pT G p1100 1C), car- bon transport takes place in three stages: (i) CO adsorp- tion on the silicon dioxide, (ii) diffusion through the SiO 2 and (iii) reaction with the silicon [4]. We can suppose that Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/mssp Materials Science in Semiconductor Processing ARTICLE IN PRESS 1369-8001/$ - see front matter & 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.mssp.2008.10.004 Ã Corresponding author. Tel.: +390512095172; fax: +390512095113. E-mail address: filippo.fabbri6@unibo.it (F. Fabbri). Materials Science in Semiconductor Processing 11 (2008) 179–181