Growth Mechanism and Chemical Structure of Amorphous Hydrogenated Silicon Carbide (a‐SiC:H) Films Formed by Remote Hydrogen Microwave Plasma CVD From a Triethylsilane Precursor: Part 1

Abstract

Amorphous hydrogenated silicon carbide (a-SiC:H) films are produced by remote microwave hydrogen plasma (RHP)CVD using triethylsilane (TrES) as the single-source precursor. The reactivity of particular bonds of the precursor in the activation step is examined using tetraethylsilane as a model compound for the RHP-CVD experiments. The susceptibility of a TrES precursor towards film formation is characterized by determining the yield of RHP-CVD and comparing it with that of the trimethylsilane precursor. The effect of substrate temperature (T s ) on the rate of the RHP-CVD process, chemical composition, and chemical structure of the resulting a-SiC:H films is reported. The substrate temperature dependence of the film growth rate implies that film growth is independent of the temperature and RHP-CVD is a mass transport-limited process. The examination of the a-SiC:H films, performed by means of X-ray photoelectron spectroscopy (XPS), elastic recoil detection analysis (ERDA), and Fourier transform infrared absorption spectroscopy (FTIR), reveals that the increase in the substrate temperature from 30 -C to 400 -C causes the elimination of organic moieties from the film and the formation of a Si-carbidic network structure. On the basis of the results of the structural study, the chemistry involved in film formation is proposed.

Properties of Amorphous Hydrogenated Silicon Carbide (a‐SiC:H) Films Formed by Remote Hydrogen Microwave Plasma CVD From a Triethylsilane Precursor: Part 2

“…[15] The length of linear segments and the specific Full Paper volume of the film decrease with enhanced crosslinking, thus giving rise to film density as shown by the plots in Figure 3. The significantly higher densities observed for the TrMS RHP-CVD films (r ¼ 1.7-2.1 g cm À3 for T s ¼ 30-400 8C, Fig.…”

“…3) may be ascribed to shorter crosslinks formed via the thermal reactions of the SiMe groups compared to those resulting from the reactions of the SiEt groups. [15] The much lower densities of TrES PCVD films (r ¼ 1.1-1.3 g cm À3 for…”

“…For this purpose, we used the film compositional and structural parameters expressing, respectively, the X-ray photoelectron spectroscopy (XPS) atomic ratio Si/C and relative integrated intensity of IR absorption band from the Si-C bonds, which have been reported in the first part of this work. [15] Properties of the examined a-SiC:H films are compared with those of the films formed from TrES by conventional PCVD and described in the literature. [5] 2.…”

Reactivity of organosilicon precursors in remote hydrogen microwave plasma chemical vapor deposition of silicon carbide and silicon carbonitride thin‐film coatings

“…The reaction described by equation (18) seems to be slightly endothermic and needs only a little energy to proceed.…”

“…The susceptibility of particular bonds in the molecules of investigated precursors to react with atomic hydrogen was estimated by our earlier comparative RP-CVD experiments involving some permethylated model compounds, such as tetramethylsilane, [14,17] tetraethylsilane, [18] bis(trimethylsilyl)methane, [17] (dimethylamino)trimethylsilane [19] and hexamethyldisilazne, [20] which are known as effective filmforming precursors for DP-CVD. [21 -23] The inability of these compounds to form films found for all RP-CVD experiments proved that the C-H, C-C, Si-C, Si-N, C-N and N-H bonds are nonreactive, whereas the observed ability of investigated precursors DMS, TrMS, TrES, HMDS, DTMSM, BDMSE, DMADMS, BDMAMS, TDMAS and TMDSN to form films can be attributed to the major role of their Si-H or Si-Si bonds in the activation step of the investigated RP-CVD process.…”