Low-pressure synthesis and characterization of multiphase SiC by HWCVD using

abstract Silicon carbide (SiC) thin films were deposited by low-pressure hot wire chemical vapor deposition(HWCVD) technique using SiH 4 and CH 4 gas precursors with no hydrogen dilution. Spectroscopic andstructural properties of the films deposited at various methane flow rate (10e100 sccm) and low silaneflow rate of 0.5 sccm were investigated. The use of low methane flow rate resulted in a sharp and intenseSieC peak in the Fourier transform infrared (FTIR) absorption spectra. The XRD spectra of the filmsshowed the formation of SiC crystallites at low methane flow rate. The Raman spectroscopy measure-ments showed the coexistence of a-Si and SiC phases in the films. Increase in methane flow rateincreased the carbon incorporation and deposition rate of the SiC films but also promoted the formationof amorphous Si and SiC phases in the films. 2011 Elsevier Ltd. All rights reserved. 1. IntroductionCrystalline silicon carbide (SiC) film has become an excellentcandidate to be used in various optoelectronic devices due to itssuperior optical, electrical, and thermal properties such as widebandgap,highelectronmobility,andhighbreakdownfield,etc.[1].For example, its application in solar cell windows layer, colorsensors, thin filmlightemitting, anddetectingdevices isreasonablyexpected [2e5].Itisdifficult to produce crystallinephaseofSiCthinfilm using most of the established CVD techniques, as microcrys-talline SiC films have been reported to form, a phase mixture of Sicrystallites and amorphous SiC [6]. However, it is widely recognizedthat high substrate temperature (>1000 C) is usually required forpreparationofhigh-qualitycrystallineSiCfilms,whereasformostofoptoelectronic applications low temperature preparation techniqueis required [7]. Very recently, hot wire chemical vapor deposition(HWCVD) has been successfully employed to grow nanocrystallinethin filmsof SiC from SiH