Influence of silane partial pressure on the properties of amorphous SiCN films prepared by ECR-CVD

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.

mentioning

confidence: 59%

mentioning

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

“…As can be noted from Table 1, the films exhibit very high hardness (H = 30 GPa and 27 GPa) and elastic modulus (E = 296 GPa and 210 GPa), as well as extremely low friction coefficient (l = 0.037 and 0.036). Good mechanical properties are also reported for DP-CVD-produced a-Si:C:N:H films formed from hexamethyldisilazane using T S = 300± 450 C (H = 14±18 GPa), [12] and from ternary gas mixtures, SiH 4 /CH 4 /N 2 , using a ± 600 V substrate bias (H = 18± 33 GPa, E = 140±200 GPa, l = 0.04±0.06 against diamond), [9] and SiH 4 /C 2 H 2 /NH 3 using T S = 50±650 C (H = 5±26 GPa, E = 55±200 GPa).…”

Section: Film Propertiesmentioning

confidence: 72%

“…This material exhibits high hardness, [1±10] low friction coefficient, [7,9] strong adhesion to the substrate, [8] wide optical bandgap, [1,11±13] good field emission characteristics, [14±16] low electrical conductivity, [12,13] and outstanding high temperature oxidation resistance. [17] In view of these properties, Si:C:N films are very promising coatings for a wide range of technological applications.…”

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.

“…[27] A rougher surface of the films deposited by nitrogen RPCVD may be ascribed to the surface reactions of the excited nitrogen atoms causing some defects to the film network structure by rupturing the crosslinks. [20] For comparison, Si:C:N films deposited by the other methods, such as DPCVD from bis(trimethylsilyl)carbodii- mide, [12] electron cyclotron resonance plasma CVD from SiH 4 /CH 4 /N 2 mixture, [34] and by RF sputter deposition using a N 2 /Ar mixture as the sputtering gas and SiC as the target, [35] exhibited much rougher surfaces with the roughness varying in the ranges rms = 2.7-4.3 nm, [12] rms = 3.5-6.3 nm, [34] and rms = 15-65 nm. [35] …”

Section: Film Surface Morphologymentioning

confidence: 99%

Remote Hydrogen Microwave Plasma CVD of Silicon Carbonitride Films from a Tetramethyldisilazane Source. Part 1: Characterization of the Process and Structure of the Films

Wróbel

Chemical Vapor Deposition

2007

Silicon carbonitride (Si:C:N) films are produced by hydrogen remote microwave plasma (RP)CVD using a 1,1,3,3-tetramethyldisilazane precursor. The effect of the substrate temperature on the rate and yield of the hydrogen RPCVD process, chemical composition, chemical structure, and surface morphology of the resulting film are investigated. The Arrhenius plots of the substrate temperature dependencies of the mass-and thickness-based growth rate and growth yield of Si:C:N film imply that RPCVD is controlled by the adsorption of film-forming precursors onto the growth surface. The results of Auger electron spectroscopy (AES) and Fourier transform infrared (FTIR) examinations reveal that the increase in substrate temperature from 35°C to 400°C involves the elimination of organic groups from the film and the formation of a silicon carbonitride network structure with a predominant content of Si-C carbidic bonds. The atomic force microscopy (AFM) results show that the films are morphologically homogeneous materials of surface roughness varying in a narrow range of small values (0.9 -2.0 nm).