Dependence of chemical composition and bonding of amorphous SiC on deposition temperature and the choice of substrate

Abstract

Amorphous SiC has superior mechanical, chemical, electrical, and optical properties which are process dependent. In this study, the impact of deposition temperature and substrate choice on the chemical composition and bonding of deposited amorphous SiC is investigated, both 6 in. single-crystalline Si and oxide covered Si wafers were used as substrates. The deposition was performed in a standard low-pressure chemical vapour deposition reactor, methylsilane was used as the single precursor, and deposition temperature was set at 600 and 650°C. XPS analyses were employed to investigate the chemical composition, Si/C ratio, and chemical bonding of deposited amorphous SiC. The results demonstrate that these properties varied with deposition temperature, and the impact of substrate on them became minor when deposition temperature was raised up from 600°C to 650°C. Nearly stoichiometric amorphous SiC with higher impurity concentration was deposited on crystalline Si substrate at 600°C. Slightly carbon rich amorphous SiC films with much lower impurity concentration were prepared at 650°C on both kinds of substrates. Tetrahedral Si-C bonds were found to be the dominant bonds in all deposited amorphous SiC. No contribution from Si-H/Si-Si but from sp 2 and sp 3 C-C/C-H bonds was identified.

Microstructure and mechanical property of high growth rate SiC via continuous hot‐wire CVD

“…Since little carbon was detected in deposit by Raman spectroscopy, the C-Si peak and the C-H/C-C peak should be attributed to crystallite and amorphous SiC, respectively. 39 We can also deduce from the decreasing intensity of C-H/C-C peak that crystallite SiC becomes the main phase in deposit at high input power. X-ray diffraction is applied to study the variation of preferred orientation and stacking faults in SiC grains with increasing input power.…”

“…As shown in Figure B, except for surface oxidation induced C–O–H and C = O peaks at around 286.4 and 288.4 eV, all the C 1s peaks can be deconvoluted into two main components at ~283.3 and ~284.6 eV, which are assigned to C–Si and the C–H/C–C bonds, respectively. Since little carbon was detected in deposit by Raman spectroscopy, the C–Si peak and the C–H/C–C peak should be attributed to crystallite and amorphous SiC, respectively . We can also deduce from the decreasing intensity of C–H/C–C peak that crystallite SiC becomes the main phase in deposit at high input power.…”

Semi-transparent Si-rich SixC1−x p–i–n photovoltaic solar cell grown by hydrogen-free PECVD

“…23 Two main peaks of the C 1s orbital electron related XPS spectra are attributed to the Si-C bonds (238.2 eV) and C-C graphitic (sp 2 ) bonds (284.6 eV). 24 The intensities of the C-C and Si-C bonds are suppressed from 280 to 120 counts and from 1600 to 960 counts, respectively, when the RF plasma power reduces from 100 to 20 W. Nevertheless, the Si-C/C-C bond intensity ratio can be enhanced from 5.7 to 8 by decreasing the RF plasma powers, which indicates a better SiC phase formed at lower RF plasma environment. In particular, the result of the semi-transparent Si x C 1Àx lm at the lower RF plasma power of 20 W with hydrogen-free deposition environment when comparing with the deposition under hydrogen diluted reactant gas recipe is similar.…”

Novel Photonic Applications of Silicon Carbide

“…Differently said, the reaction kinetics are infinitely slow. However, with organometallic precursors such as monomethylsilane (MMS), a deposition temperature lower than 650 °C and down to room temperature can form a-SiC [ 78 , 79 , 80 ].…”

“…The hydrogen atoms get desorbed during this reaction. However, because of the low temperature of the process and the needed hydrogen desorption, the stoichiometry of the SiC becomes hard to control [ 80 , 81 ]. No optical study using films deposited by this process was found in the literature.…”