Properties of Nanocrystalline Cubic Silicon Carbide Thin Films Prepared by Hot-Wire Chemical Vapor Deposition Using SiH₄/CH₄/H₂ at Various Substrate Temperatures

Abstract

Silicon carbide (SiC) thin films were prepared by hot-wire chemical vapor deposition from SiH 4 /CH 4 /H 2 gases, and the influence of substrate temperature, T s (104 < T s < 434 C), on the properties of the SiC thin films was investigated. X-ray diffraction patterns and Raman scattering spectra revealed that nanocrystalline cubic SiC (nc-3C-SiC) films grew at T s above 187 C, while completely amorphous films grew at T s ¼ 104 C. Fourier transform infrared absorption spectra revealed that the crystallinity of the nc-3C-SiC was improved with increasing T s up to 282 C and remained almost unchanged with a further increase in T s from 282 to 434 C. The spin density was reduced monotonically with increasing T s .

Nano-sized silicon carbide: synthesis, structure and properties

“…Figure 5 shows examples of the temperature evolution of the Raman, XRD and IR spectra for SiC films synthesized by reactive magnetron sputtering in the argon 32 and hydrogen ± argon plasma 35 and also by CVD onto a molyb-denum wire from a mixture of silane, methane and hydrogen. 37 The characteristic features of these spectra were discussed in detail 34 as applied to films, nanowires, nanoneedles and other SiC nanoobjects synthesized on silicon substrates by pulsed laser irradiation. Particularly, the presence of small reflexes in the vicinity of the pronounced (111) peak in b-SiC XRD patterns was mentioned, which was associated with stacking defects.…”

Nanocrystalline cubic silicon carbide thin films for the window layer of solar cells deposited by hot wire CVD

“…[8,9]. A small shoulder at ~33.8 o could be due to the hexagonal (4H) phase of SiC [9]. The broad peak between ~23-29 o in 3 mbar and 5 mbar sample may be due to the amorphous nature of the substrate as these samples are thinner compared to 2 mbar and 4 mbar sample.…”

“…The shift towards lower wave number compared to c-Si in Raman spectrum could be due to the small size of crystallites. For films prepared at PP ≥ 2 mbar, the Raman spectra clearly reveal the nanocrystalline nature of the 3C-SiC as characteristic peaks corresponding to 3C-SiC TO and longitudinal optical (LO) mode appear at 780 cm -1 and 960 cm -1 respectively [8,9]. The broad peak near 400-600 cm -1 could be due to the overlap between different transverse acoustic (TA) and longitudinal acoustic (LA) mode of 3C-SiC as well as amorphous silicon (a-Si) [10].…”

“…The broad peak near 400-600 cm -1 could be due to the overlap between different transverse acoustic (TA) and longitudinal acoustic (LA) mode of 3C-SiC as well as amorphous silicon (a-Si) [10]. [8,9]. A small shoulder at ~33.8 o could be due to the hexagonal (4H) phase of SiC [9].…”

Synthesis of nanocrystalline silicon carbide thin films by HW-CVD using ethane carbon precursor for photo detector application

“…The PE-CVD technique has an integration advantage in the device fabrication with the current technologies employed in semiconductor industries but this technique has the problem of ion damage on the growing surface and interfaces because of use of high power density, low deposition rate due to use of high hydrogen dilution and low carbon incorporation efficiency. In recent years, hot wire chemical vapor deposition (HW-CVD) technique has emerged as a promising technique to deposit such films at relatively low substrate temperature [18][19][20][21][22]. The two major advantages of employing HW-CVD method for the synthesis of SiC coatings are the absence of the deleterious electrons and ions and surface charges which avoid of powder formation and second is high dissociation rate of source gases which leads to higher deposition rate.…”