Remote hydrogen–nitrogen plasma chemical vapor deposition from a tetramethyldisilazane source. Part 1. Mechanism of the process, structure and surface morphology of deposited amorphous hydrogenated silicon carbonitride filmsElectronic supplementary information (ESI) available: deconvoluted emission and IR spectra of a-Si–N–C–H films. See http://www.rsc.org/suppdata/jm/b2/b211415c/

Chemical Vapor Deposition

Uznański

et al. 2010

Owing to a complex structure composed of carbidic Si-C and nitridic Si-N and C-N units, silicon carbonitride (SiCN) films display many unique properties. They are promising coating materials in advanced technology. Most recent reports [1][2][3][4][5][6] revealed many unique features of SiCN films which may be used as hard, dense, and high temperatureand corrosion-resistant coatings for metals (giving excellent tribological behavior), as well as highly selective gas separation membranes. [7] Of the various methods based on the gas-phase processes which are used for the formation of SiCN films, remote microwave plasma (RP)CVD from organosilicon precursors, developed in our laboratory, appeared to be a very useful technique, offering wellcontrolled deposition conditions free of film-damaging effects.[2]In this communication we report on the fabrication of amorphous SiCN films by RPCVD using hydrogen as an upstream gas for microwave plasma generation, and tris(dimethylamino)silane (TrDMAS), (Me 2 N) 3 SiH, as a novel single-source precursor, being a carrier of Si-N and C-N units. Owing to the presence of hydrosilyl, Si-H bonds in the TrDMAS molecule, this precursor is strongly reactive with hydrogen atoms fed from the plasma region to the CVD reactor. Moreover, the dimethylaminosilyl, Me 2 NSi, groups of the precursor may easily undergo a condensation reaction at elevated temperatures. The present study was undertaken in view of our earlier reports on the SiCN films produced by RPCVD from other aminosilane precursors, such as (dimethylamino)dimethylsilane, [8][9][10] Me 2 NSiHMe 2 , and bis(dimethylamino)methylsilane, [11,12] (Me 2 N) 2 SiHMe, which revealed their very promising useful properties. We describe the effect of substrate temperature on the growth rate, chemical structure, surface morphology, density, and photoluminescence of produced SiCN films. Figure 1 shows the effect of thermal activation on the kinetics of SiCN film growth from TrDMAS characterized by the substrate temperature, T S , dependency of the thickness-based film growth rate, r d , determined in the form of an Arrhenius plot. The decrease of r d with increasing T S (Fig. 1) and the negative value of the apparent activation energy E a ¼ À14 kJ mol À1 calculated from the slope of the Arrhenius plot, implies that film growth is mainly limited by the adsorption of film-forming precursors from the gas phase onto the growth surface. In this case, the apparent activation energy is expressed as E a ¼ E r þ DH ad , where E r denotes the activation energy of the film-forming reaction and DH ad is the apparent heat of adsorption of the film-forming precursors onto the growth surface and has a negative value, [13,14] thus the negative E a values are due to the fact that the absolute DH ad value is higher than the E r value.

Section: Methodsmentioning

confidence: 99%

Silicon Carbonitride (SiCN) Films by Remote Hydrogen Microwave Plasma CVD from Tris(dimethylamino)silane as Novel Single‐Source Precursor

Wróbel

Chemical Vapor Deposition

Uznański

et al. 2010

“…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.…”

Section: Reaction Systemmentioning

confidence: 99%

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

Wróbel

Walkiewicz-Pietrzykowska

2009

Applied Organom Chemis

Self Cite

A number of organosilicon precursors for silicon carbide and silicon carbonitride thin-film coatings, such as silanes, carbosilanes, aminosilanes, and disilazane, respectively, were characterized in terms of their reactivity in a remote microwave plasma chemical vapor deposition process, which was induced using hydrogen as plasma generating gas. The process displayed high selectivity with respect to the activating species and the chemical bonds in the molecular structure of the precursors. In view of very short life times of excited hydrogen plasma species the activation step takes place with an exclusive contribution of ground-state hydrogen atoms. The C-H, C-C, Si-C, Si-N, C-N and N-H bonds present in the molecules of the precursors are non-reactive and only the Si-H or Si-Si bonds play a key role in the activation step. The reactivity of the precursors was characterized in a quantitative way by the yield of the film growth parameter. The yield parameter expressing the mass of film per unit mass of the precursor fed to the reactor was calculated from the slopes of linear plots of time dependencies of film mass and precursor mass, which were determined for each investigated precursor. The reactivity of the precursors was found to be strongly dependent on the number of the Si-H units present in their molecules and those containing two Si-H units appeared to be most reactive.

“…Owing to these aspects, RP-CVD is a very advantageous technique for the production of defect-free and morphologically homogeneous Si:C:N films, as revealed by our recent study. [27] The results of earlier studies [26,27] on a-Si:C:N:H films formed from a 1,1,3,3-tetramethyldisilazane, (Me 2 HSi) 2 NH, precursor by remote hydrogen-nitrogen plasma CVD have proved that the contribution of Si±NH±Si and Si±NH±C bonds in the film (incorporated from the precursor, and formed by the insertion of hydronitrene HN from the gas phase, respectively) causes substantial deterioration in its mechanical properties. A significant decrease of hardness and elastic modulus with increasing content of the NH units in the film was noted.…”

Section: Introductionmentioning

confidence: 99%

“…A significant decrease of hardness and elastic modulus with increasing content of the NH units in the film was noted. [27,28] In the present work, we overcame these drawbacks by using (dimethylamino)dimethylsilane (DMADMS), Me 2 -NSiHMe 2 , as a novel single-source precursor for the production of amorphous hydrogenated silicon carbonitride (a-Si:C:N:H) films by RP-CVD, and hydrogen as the upstream gas for plasma generation. The DMADMS precursor was selected due to the presence of the Si±H bond, highly reactive in the atomic hydrogen environment, and the contribution of the Si±N±C bond with tertiary nitrogen atom, which may be readily incorporated into the film structure.…”

Section: Introductionmentioning

confidence: 99%

Silicon Carbonitride Films Produced by Remote Hydrogen Microwave Plasma CVD Using a (Dimethylamino)dimethylsilane Precursor

Wróbel²,

Kivitorma

et al. 2005

Chem. Vap. Deposition

Amorphous hydrogenated silicon carbonitride (a-Si:C:N:H) films were produced by remote microwave hydrogen plasma CVD (RP-CVD) using (dimethylamino)dimethylsilane as a single-source precursor. The reactivity of the precursor with atomic hydrogen was characterized using (dimethylamino)trimethylsilane as a model compound. The effects of the substrate temperature (T S ) on the kinetics of the RP-CVD process, and the chemical composition and structure of the resulting film, have been investigated. The temperature dependencies of the mass-and thickness-based film growth rates imply that, for a low substrate temperature range (T S = 30±100 C), film growth is limited by desorption of film-forming precursors, whereas in a high substrate temperature range (T S = 100±400 C) film growth is independent of the temperature, and the rate of RP-CVD is masstransport limited. The increase of the substrate temperature from 30 C to 400 C causes the elimination of organic moieties from the film and the formation of a Si±N and Si±C network structure. The films produced at T S = 300 C were found to be dense materials exhibiting excellent morphological homogeneity, high hardness, and an extremely low friction coefficient. In view of these properties, a-Si:C:N:H films produced by RP-CVD seem to be promising coatings for tribological use.