Deposition Of Silicon Carbide Films Research Articles

Molecular Dynamics Simulation of Thin Silicon Carbide Films Formation by the Electrolytic Method.

Silicon carbide is successfully implemented in semiconductor technology; it is also used in systems operating under aggressive environmental conditions, including high temperatures and radiation exposure. In the present work, molecular dynamics modeling of the electrolytic deposition of silicon carbide films on copper, nickel, and graphite substrates in a fluoride melt is carried out. Various mechanisms of SiC film growth on graphite and metal substrates were observed. Two types of potentials (Tersoff and Morse) are used to describe the interaction between the film and the graphite substrate. In the case of the Morse potential, a 1.5 times higher adhesion energy of the SiC film to graphite and a higher crystallinity of the film was observed than is the case of the Tersoff potential. The growth rate of clusters on metal substrates has been determined. The detailed structure of the films was studied by the method of statistical geometry based on the construction of Voronoi polyhedra. The film growth based on the use of the Morse potential is compared with a heteroepitaxial electrodeposition model. The results of this work are important for the development of a technology for obtaining thin films of silicon carbide with stable chemical properties, high thermal conductivity, low thermal expansion coefficient, and good wear resistance.

Low-energy Ar+ ion beam induced chemical vapor deposition of silicon carbide films using dimethylsilane

In this paper, a methodology for silicon carbide (SiC) film formation by ion beam induced chemical vapor deposition (IBICVD) using dimethylsilane (DMS) is presented. Both pure DMS gas and Ar+ ion beam were simultaneously injected to a Si substrate. The Ar+ ion energy was 100 eV. The Si substrate temperature was 400, 600, or 800 °C. The duration of each ion beam injection experiment was 10 h. When the substrate temperature was 400 °C, no film formation occurred by the IBICVD experiment. In the case of 600 °C, a film was found to be formed on the substrate by the injection of both DMS gas and Ar+ ion beam. Although Fourier transform infrared (FTIR) spectroscopy measurement of the film showed that the film consisted of SiC, the film thickness was not enough to analyze the film characteristics further. When the Si substrate was set at 800 °C, a film was formed on the substrate by IBICVD. FTIR, X-ray diffraction, and X-ray photoelectron spectroscopy (XPS) measurements of the film showed the occurrence of SiC deposition. The XPS measurement also showed that the atomic concentration ratio of carbon to silicon (C/Si ratio) of the film was 1.36. Therefore, excessive C atoms were incorporated to the deposited films. On the contrary, the C/Si ratio of a SiC film prepared by the thermal CVD method using DMS was 1.88. These results suggest that the Ar+ ion beam induced chemical vapor deposition using DMS is useful for reducing of the amount of C atoms to be excessively included in the film.

Effect of a SiC seed layer grown at different temperatures on SiC film deposition on top of an AlN/Si(110) substrate

We have formed silicon carbide (SiC) seed layers at various substrate temperatures by ultralow-pressure chemical vapor deposition using monomethylsilane (CH3SiH3) on aluminum nitride (AlN) films grown on off-axis Si(110) substrates. After that, we grew SiC films on the seed layers by pulsed laser deposition using a SiC target. We investigated the effects of the seed layers formed at various temperatures on the crystallinity and surface morphology of the SiC films thereon. The SiC films grown on the seed layers tended to have lower surface roughnesses than the film grown directly on the AlN film. The SiC film grown on the seed layer formed at 600 °C on the AlN film had the best crystallinity among the films. The formation of the seed layers had an effect on the relaxation of the internal stress in the SiC films. The SiC film can be used to grow epitaxial graphene by high-temperature annealing, and the AlN layer on Si plays a role in insulating graphene devices from the Si substrate. Therefore, the graphene transistors are one of the possible applications for epitaxial graphene grown on SiC/AlN/Si.

Quick and Practical Cleaning Process for Silicon Carbide Epitaxial Reactor

In order to develop a quick and practical cleaning process for the silicon carbide chemical vapor deposition reactor, the pyrolytic carbon-coated susceptor was used. The 30-μm-thick silicon carbide film was formed on the susceptor; the film was cleaning by chlorine trifluoride gas at 460 °C for 15 min. The remained fluorine was removed by the annealing at 900 °C in ambient hydrogen. The pyrolytic carbon surface did not suffer from any damage, because the pyrolytic carbon film surface morphology after the cleaning process was the same as that before the silicon carbide film deposition.

Cleaning Process for Using Chlorine Trifluoride Gas Silicon Carbide Chemical Vapor Deposition Reactor

The silicon carbide CVD reactor cleaning process was studied by means of detaching silicon carbide particles, which was formed on the silicon carbide coated carbon susceptor surface during the silicon carbide film deposition. The contact points between the particles and the susceptor surface were etched using chlorine trifluoride gas at temperatures lower than 290 °C for 120 min. During this process, the carbon susceptor covered with the silicon carbide coating film suffered from little damage while achieving cleaning.

Application of Ion Beam Induced Chemical Vapor Deposition for SiC Film Formation on Si Substrates using Methylsilane

We propose an experimental methodology for producing silicon carbide (SiC) films on Si substrates using an ion beam induced chemical vapor deposition (IBICVD) technique with methylsilane (SiH3CH3) as a gas source. Both methylsilane gas (1.2 sccm) and Ar ion beam (100 eV, 5μA) were simultaneously introduced onto Si(100) substrates. Temperatures of Si substrates were set at 600, 700, or 800°C. A SiC thin film was formed by the simultaneous introduction of methylsilane and Ar ions onto the Si substrate when the substrate temperature was 600°C. On the other hand, in the cases of 700 and 800°C, SiC films were formed by methylsilane gas alone and SiC film deposition rates by methylsilane gas with the Ar ion beam were approximately identical with those obtained without the Ar ion beam. We therefore conclude that the IBICVD technique with methylsilane is useful for SiC film formation on Si at relatively low substrate temperatures. [DOI: 10.1380/ejssnt.2015.174]

Cleaning Process Applicable to Silicon Carbide Chemical Vapor Deposition Reactor

The reactor cleaning process applicable to the silicon carbide chemical vapor deposition was designed and developed. The large silicon carbide particles formed on the carbon susceptor surface during the silicon carbide film deposition could be removed by etching the narrow contact regions between the particles and the susceptor surface using chlorine trifluoride gas at temperatures lower than 290°C. During this process, the carbon susceptor covered with the silicon carbide coating film did not suffer considerable damage. Thus, the reactor cleaning by detaching the silicon carbide particles while maintaining the silicon carbide coating film is possible when chlorine trifluoride gas is used at low temperatures.

Langasite Crystal Microbalance Used for In-Situ Monitoring of Amorphous Silicon Carbide Film Deposition

An in-situ measurement method using a langasite crystal microbalance (LCM) was evaluated for monitoring chemical vapor deposition. When an amorphous silicon carbide film was formed from monomethylsilane gas at 600°C, the weight increase caused by the film deposition could be measured by the LCM frequency decrease after reaching the steady-state of various parameters, such as the gas density, the gas viscosity, and the temperature, in the reactor. The changing rate of the LCM frequency at the monomethylsilane gas concentration of 5% was −10 Hz/s. This value corresponded to the silicon carbide film deposition rate of 0.4 nm/min, which was evaluated from the film thickness obtained using the same growth condition. Although the LCM frequency also depends on the pressure and temperature, the film deposition rate can be more accurately controlled by the LCM in-situ monitoring when the film deposition rate is on the order of nm/min.

Langasite Crystal Microbalance for Development of Reactive Surface Preparation of Silicon Carbide Film Deposition from Monomethylsilane Gas

A silicon carbide chemical vapor deposition (CVD) process at room temperature was developed using monomethylsilane (MMS) gas by an in situ measurement method using a langasite crystal microbalance (LCM). The phenomenon occurring on the LCM was evaluated by monitoring the frequency change during the processes and by comparing the frequencies in a steady state in ambient hydrogen without the use of any additional gases. The entire process was performed on the LCM, which could be used to evaluate the reactive surface preparation and the silicon carbide film deposition. To produce a reactive surface, a silicon-rich thin film was prepared by the CVD technique using MMS gas at 800 °C. Because the LCM frequency continuously decreased along with the MMS gas supply at room temperature, the silicon carbide film deposition was found to be continuous for 1 min.

Langasite Crystal Microbalance for Development of Reactive Surface Preparation of Silicon Carbide Film Deposition from Monomethylsilane Gas

Langasite Crystal Microbalance for Development of Reactive Surface Preparation of Silicon Carbide Film Deposition from Monomethylsilane Gas

Mechanism of Silicon Carbide Film Deposition at Room Temperature Using Monomethylsilane Gas

The mechanism of silicon carbide chemical vapor deposition on a silicon surface using a monomethylsilane gas at room temperature was studied. Because the silicon carbide film surface tended to have large hillocks at the high monomethylsilane gas concentrations, the surface chemical reaction for the silicon carbide film formation was considered to include a three-dimensional pass, even at room temperature. The composition of the obtained film was consistent with that expected from the film formation process. Because the lowest temperature of hydrogen annealing for enabling the silicon carbide film formation coincided with the lowest temperature for practically removing the native oxide film by the hydrogen annealing, the silicon dimer at the silicon surface formed by the hydrogen annealing and the cooling in ambient hydrogen was concluded to play a key role.

Deposition of SiC films by ion-enhanced plasma chemical vapor deposition using tetramethylsilane + H 2

Silicon carbide film deposition on Si surface has been demonstrated by means of an ion-enhanced plasma chemical vapor deposition (CVD) using a tetramethylsilane + H 2 gas mixture. The plasma reactor used equips a triode system in which a substrate bias circuit with two diodes is employed to accelerate the deposition through ion bombardment processes. The deposition rate of the SiC film was 0.75 μm/h at the substrate temperature, T sub, of 750 °C and the bias voltage, V b, of − 200 V. The Vickers hardness and the refractive index of the film were 3500 Hv and 2.7, respectively. The infrared transmission measurement showed that the film contains plenty of Si–C bonds. The X-ray diffraction pattern suggested that the deposited SiC film is in a state of α-SiC crystal with (100) orientation.

Plasma assisted process for deposition of silicon carbide thin films

Abstract Silicon carbide (SiC) thin films were deposited on silicon substrate by the RF plasma chemical method, operating at a frequency of 13.56 MHz. Two different plasma assisted chemical vapor deposition (CVD) technologies were attempted: direct plasma CVD with reaction gas of CH 3 SiCl 3 and remote plasma CVD with SiH 4 + C 3 H 8 . The film deposition rate of SiC was linearly increased with the plasma power when the substrate temperature was fixed to 300 °C. The measurement of the photon absorption reveals that the band gaps of the electron energy state were to be 2.39 eV for Si 0.5 C 0.5 , and 2.51 eV for Si 0.4 C 0.6 , respectively. In the high-density regime of the RF plasma, the methyl-radicals decompose easily and increase the carbon concentration in the plasma and result in the growing films. The yield of the remote plasma CVD was estimated as 70.8% when the flow rate of SiH 4 + C 3 H 8 gases was kept to 15SCCM and 10SCCM, respectively. The deposition of SiC films with remote plasma CVD followed by a laser treatment would be the optimal process technology to obtain the high quality poly-crystalline SiC film.

Deposition of silicon carbide films using a high vacuum metalorganic chemical vapor deposition method with a single source precursor: Study of their structural properties

Silicon carbide (SiC) thin films were prepared on Si(100) substrates by high vacuum metalorganic chemical vapor deposition using a single-source precursor at various growth temperatures in the range of 700–1000 °C. The precursor is diethylmethylsilane, and is used without carrier gas. The effects of substrate temperature as well as deposition time on the crystal growth were investigated. The optimum temperature for the formation of high quality polycrystalline SiC thin films was found to be 900 °C on the basis of x-ray diffraction and transmission electron diffraction results. X-ray photoemission spectroscopy shows that SiC films grown at 900 °C have slightly carbon-rich compositions (Si:C=1:1.2) in the surface region, but stoichiometric composition in the bulk. Scanning and transmission electron microscope images show the influence of substrate temperature on the grain size and crystallinity of the films. Large grain sizes and high quality crystallinity can be obtained below 900 °C.

Thermal Chemical Vapor Deposition of Silicon Carbide Films as Protective Coatings for Microfluidic Structures

ABSTRACTAmorphous silicon carbide (SiC) films were deposited on silicon substrates by thermal chemical vapor deposition (TCVD) technique, at substrate temperatures ranging from 620 °C - 850 °C. A novel, single-source halide free precursor, SP-4000, belonging to the family of polysilenemethylenes (PSM) (nominal structure [-SiH2-CH2-]n, n = 2–8 including branched and cyclic isomers) was used as source. Argon was used, as both the precursor carrier gas and the dilution gas. Other reactants, such as hydrogen or hydrocarbons, were not used. The deposition yielded films with Si/C ratio of 1±0.2. The highest achieved growth rate was 83 nm/min.The modulus of elasticity and the nanohardness of the SiC films were measured with the aid of a nanoindenter at various depths, which did not exceed 25% of the film thickness. The average nanohardness at indentation depths of approximately 10% of the film thickness was measured up to 13 ± 4 GPa. The results of the nanoindentation will be discussed in conjunction with the microstructural analysis of the films.In addition, the development of a viable TCVD SiC process presents significant opportunities in the nano/micro systems field. In particular, the ability to custom tailor the surfaces of microfluidic structures allows for the development of valves, pumps and channels for use in corrosive or high temperature environments. Initial results from the deposition of SiC films on prototype microfluidic components will be presented.

Light emission of the silicon carbide nanoclusters embedded into porous silicon

The silicon carbide (SiC) films deposited onto porous silicon have been used as modification and functional layer. The different regions (long wave and short wave) of light emission were observed after deposition of SiC film with different thicknesses on the porous silicon surface. The thin (∼50 nm) SiC film deposition leads to decrease of photoluminescence (PL) intensity up to three times in long-wave region (700 nm) when compared with initial porous silicon, and appearance of the high-energy emission (450 nm). However, the thick (∼200 nm) SiC film deposition caused the quenching of long-wave emission and only high-energy emission was observed. The rapid thermal annealing (RTA) treatment of the structures was carried out. The result of RTA for porous Si+SiC film structure was the substantial transformation of the spectral bands. The long-wave band (∼600 nm) in spectrum of annealed porous Si+SiC structures being as intensive as red band (∼700 nm) for initial porous Si appeared. The band was attributed to emission of SiC nanoclusters formed on Si quantum wires.

Deposition of 3C-SiC films using ECR plasma of methylsilane

We deposited silicon carbide (SiC) films formation using electron cyclotron resonance (ECR) plasma of methylsilane (SiH 3CH 3), and investigated the influence of a carrier gas (Ar or Xe). The SiC film deposition on Si (1 0 0) was carried out at a relatively low temperature of 750°C. By using ECR plasma with a carrier gas, Si–H bonds were not contained in the deposited films. Although surface morphology was very smooth in the case of using Ar carrier gas, crystallinity of the film was poor. This indicated that the film was eroded by carrier gas because surface morphologies were changed with different momentum values of ion.

Deposition of silicon carbide films by plasma enhanced chemical vapour deposition

Thin films of silicon carbide have been prepared by plasma enhanced chemical vapour deposition using Si(Si(CH 3) 3) 4 as a precursor. This compound is stable against moisture and air and has a high vapour pressure. Furthermore, the compositions of the films prepared from this precursor show very little dependence on the plasma parameters. Consequently, this precursor is especially suited for practical applications of hard coatings.

Laser reactive ablation deposition of silicon carbide films

Silicon carbide films were deposited on Si wafers (at room temperature and 150°C) by XeCl laser (fluence 5 J/cm2, pulse duration 30 ns, repetition rate 10 Hz) ablation of Si in low pressure (0.25–6 mbar) CH4 atmosphere. The deposits were characterized by different diagnostic techniques (XRD, XPS, RBS, etc.). Polycrystalline stoichiometric silicon carbide films ∼ 1 μm thick were obtained under specific conditions after ∼ 104 laser pulses.

Some Properties of Vapor Deposited SiC

A process for the vapor deposition of silicon carbide films on silicon substrates using the hydrogen reduction of silicon tetrachloride and the pyrolysis of a hydrocarbon such as toluene was developed. At the optimum deposition temperature of , the deposition rate using 0.89% silicon tetrachloride and 0.18% toluene was 1.6 µ/min. Films deposited at less than 0.18% toluene, with a fixed silicon tetrachloride concentration of 0.89%, were attacked by “Planar etch,” while those deposited at or above 0.18% toluene were not; the electrical resistance decreased, however. When the silicon tetrachloride concentration was varied from 0.7 to 0.9% at 0.18% toluene, the electrical resistance of the films was greater than one hundred megohms. The thermal coefficient of expansion was tailored to be less than, equal to, or greater than that of silicon by changing the concentration of silicon tetrachloride from 0.6 to 1.2% at 0.18% toluene. The refractive index of the films also changed with the change in silicon tetrachloride concentration. Infrared transmission data on films deposited at 0.18% toluene and 0.89% silicon tetrachloride were identical to those for bulk silicon carbide. X‐ray diffraction studies showed that the films were normally polycrystalline and consisted of both alpha and beta phases, however, epitaxial silicon carbide was observed in some cases.