scholarly journals Deposition Kinetics of Thin Silica-Like Coatings in a Large Plasma Reactor

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3238 ◽  
Author(s):  
Žiga Gosar ◽  
Denis Đonlagić ◽  
Simon Pevec ◽  
Janez Kovač ◽  
Miran Mozetič ◽  
...  
Keyword(s):  
Deposition Rate ◽  
Plasma Reactor ◽  
Chemical Vapor ◽  
Processing Parameters ◽  
Ion Density ◽  
Capacitively Coupled ◽  
Rotary Pumps ◽  
Kinetics Of ◽  
Radio Frequency Discharge ◽  
Deposited Films

An industrial size plasma reactor of 5 m3 volume was used to study the deposition of silica-like coatings by the plasma-enhanced chemical vapor deposition (PECVD) method. The plasma was sustained by an asymmetrical capacitively coupled radio-frequency discharge at a frequency of 40 kHz and power up to 7 kW. Hexamethyldisilioxane (HMDSO) was introduced continuously at different flows of up to 200 sccm upon pumping with a combination of roots and rotary pumps at an effective pumping speed between 25 and 70 L/s to enable suitable gas residence time in the plasma reactor. The deposition rate and ion density were measured continuously during the plasma process. Both parameters were almost perfectly constant with time, and the deposition rate increased linearly in the range of HMDSO flows from 25 to 160 sccm. The plasma density was of the order of 1014 m−3, indicating an extremely low ionization fraction which decreased with increasing flow from approximately 2 × 10−7 to 6 × 10−8. The correlations between the processing parameters and the properties of deposited films are drawn and discussed.

scholarly journals Distribution of the Deposition Rates in an Industrial-Size PECVD Reactor Using HMDSO Precursor

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1218
Author(s):  
Žiga Gosar ◽  
Denis Đonlagić ◽  
Simon Pevec ◽  
Bojan Gergič ◽  
Miran Mozetič ◽  
...  
Keyword(s):  
Deposition Rate ◽  
Protective Coatings ◽  
Chemical Vapor ◽  
Rf Discharge ◽  
Gas Phase Reactions ◽  
Deposition Rates ◽  
Capacitively Coupled ◽  
Rf Discharges ◽  
Rotary Pumps ◽  
Order Of Magnitude

The deposition rates of protective coatings resembling polydimethylsiloxane (PDMS) were measured with numerous sensors placed at different positions on the walls of a plasma-enhanced chemical vapor deposition (PECVD) reactor with a volume of approximately 5 m3. The plasma was maintained by an asymmetric capacitively coupled radiofrequency (RF) discharge using a generator with a frequency 40 kHz and an adjustable power of up to 8 kW. Hexamethyldisiloxane (HMDSO) was leaked into the reactor at 130 sccm with continuous pumping using roots pumps with a nominal pumping speed of 8800 m3 h−1 backed by rotary pumps with a nominal pumping speed of 1260 m3 h−1. Deposition rates were measured versus the discharge power in an empty reactor and a reactor loaded with samples. The highest deposition rate of approximately 15 nm min–1 was observed in an empty reactor close to the powered electrodes and the lowest of approximately 1 nm min–1 was observed close to the precursor inlet. The deposition rate was about an order of magnitude lower if the reactor was fully loaded with the samples, and the ratio between deposition rates in an empty reactor and loaded reactor was the largest far from the powered electrodes. The results were explained by the loss of plasma radicals on the surfaces of the materials facing the plasma and by the peculiarities of the gas-phase reactions typical for asymmetric RF discharges.

scholarly journals Enhancement of Cleanliness and Deposition Rate by Understanding the Multiple Roles of the Showerhead Electrode in a Capacitively Coupled Plasma Reactor

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 999
Author(s):  
Ho Jun Kim
Keyword(s):  
Deposition Rate ◽  
Complex Geometry ◽  
Plasma Reactor ◽  
Three Dimensional ◽  
Multiple Roles ◽  
Capacitively Coupled ◽  
Large Particles ◽  
Capacitively Coupled Plasma ◽  
Physical Phenomena ◽  
Number Of Particles

Increasing the productivity of a showerhead-type capacitively coupled plasma (CCP) reactor requires an in-depth understanding of various physical phenomena related to the showerhead, which is not only responsible for gas distribution, but also acts as the electrode. Thus, we investigated how to enhance the cleanliness and deposition rate by studying the multiple roles of the showerhead electrode in a CCP reactor. We analyzed the gas transport in a three-dimensional complex geometry, and the SiH4/He discharges were simulated in a two-dimensional simplified geometry. The process volume was installed between the showerhead electrode (radio frequency powered) and the heater electrode (grounded). Our aim of research was to determine the extent to which the heated showerhead contributed to increasing the deposition rate and to reducing the size of the large particles generated during processing. The temperature of the showerhead was increased to experimentally measure the number of particles transported onto the heater to demonstrate the effects thereof on the decrease in contamination. The number of particles larger than 45 nm decreased by approximately 93% when the showerhead temperature increased from 373 to 553 K.

Growth kinetics of chemically vapor deposited SiO2 films from silane oxidation

1998 ◽  
Vol 13 (8) ◽  
pp. 2308-2314 ◽  
Author(s):  
Fernando Ojeda ◽  
Alejandro Castro-García ◽  
Cristina Gómez-Aleixandre ◽  
José María Albella
Keyword(s):  
Gas Phase ◽  
Deposition Rate ◽  
Growth Kinetics ◽  
Film Growth ◽  
Chemical Vapor ◽  
Intermediate Species ◽  
Pressure Oxygen ◽  
Pressure Chemical ◽  
Different Temperatures ◽  
Kinetics Of

The growth kinetics of SiO2 thin films obtained by low-pressure chemical vapor deposition (CVD) from SiH4/O2/N2 gas mixtures has been determined at different temperatures and flow rates. The results show that the film growth is originated by some intermediate species (e.g., SiOxHy) produced in the gas phase. At low temperatures the deposition rate is limited by some homogeneous reaction with an apparent activation energy of 1.42 eV. Furthermore, the observation of critical limits when total pressure, oxygen/silane flow ratio, and temperature are decreased gives support to a branching-chain mechanism of deposition. Finally, we have observed that the deposition rate shows a hysteresis behavior when varying the temperature within the 300–400 °C range, which has been attributed to the inhibition of silane oxidation by the Si–OH surface groups of the films grown on the reactor walls.

Effects Of Impurities on the Crystallization and Grain Growth of Polycrystalline Si Films

1995 ◽  
Vol 403 ◽  
Author(s):  
Jae- Cheol Paik ◽  
Kwang-Hyun Park ◽  
Woon Choi ◽  
Seung-Eui Nam ◽  
Hyoung-June Kim
Keyword(s):  
Grain Growth ◽  
Active Material ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Base Pressure ◽  
Device Performance ◽  
Lower Base ◽  
Si Films ◽  
Kinetics Of ◽  
Deposited Films

AbstractDevice-quality poly-Si films are used as the active material of poly-Si thin film transistors. Poly-Si films with high crystallinity, which have large grains and/or low intragranular defects, lead to a high device performance. The presence of O or C impurities in the deposited Si films can greatly affect the behavior of crystallization and grain growth of these films, and their resulting crystallinities. A substantial amount of O or C can be introduced in the films during deposition from residual gases in the deposition chamber. Control of base pressure during Si deposition, therefore, will be an important process parameter determining the crystallinity of these films. The effects of the base pressure on the crystallization and grain growth of deposited Si films were investigated using a high vacuum Chemical Vapor Deposition system. Lower base pressure decreases the deposition temperature for the amorphous/crystalline transition of as-deposited films. Crystallization of amorphously deposited films is also affected by base pressure. The kinetics of crystallization and crystallinities of poly-Si films after crystallization are substantially increased by reducing base pressure. Enhanced crystallization kinetics and film crystallinities can be explained by reduced inclusions of O or C impurities in Si films, thus enhancing the atomic mobility. The improved film crystallinity of poly-Si films leads to higher device performance of poly-Si TFT's.

Effects of Annealing Atmosphere on the Characteristics and Optical Properties of SiON Films Prepared Plasma Enhanced Chemical Vapor Deposition

2004 ◽  
Vol 817 ◽  
Author(s):  
Ki-Jun Yun ◽  
Dong-Ryeol Jung ◽  
Sung-Kil Hong ◽  
Jong-Ha Moon ◽  
Jin-Hyeok Kim
Keyword(s):  
Optical Properties ◽  
Deposition Rate ◽  
Flow Rate ◽  
Chemical Vapor ◽  
Processing Parameters ◽  
Nitrogen Atmosphere ◽  
Annealing Atmosphere ◽  
Flow Ratio ◽  
Rf Power ◽  
Bonding Characteristics

AbstractSiON thin films were deposited by plasma-enhanced chemical vapor deposition method at 350 °C using N2O/SiH4 gas mixtures as precursors. As-deposited SiON films were annealed in different gas atmospheres (air, N2, and O2) and at different annealing temperatures (800 oC ∼ 1100 oC). Effects of annealing atmosphere on the Si-O, Si-N, Si-H, and N-H bonding characteristics in SiON films and their structural and optical properties have been investigated. Cross-sectional and planar microstructures were characterized by scanning electron microscopy and atomic force microscopy, and crystallinity was investigated by X-ray diffraction. Chemical bonding characteristics and optical properties SiON films were studied using fourier transform infrared spectroscopy and prism coupler. Xray diffractions showed no evidence of any crystals in all SiON films. The deposition rate strongly depended on the processing parameters such as radio frequency (rf) power, N2O/SiH4 flow ratio, and SiH4 flow rate. Deposition rate increased as N2O/SiH4 flow ratio increased and SiH4 flow rate increased. It was possible to obtain SiON films with surface roughness of about 1 nm and a high deposition rate of about 4 μm/h when the processing parameters were optimized as rf power of 200 W, N2O/SiH4 flow ratio of 3, SiH4 flow rate of 100 sccm. It was observed that the intensity and the shift of the Si-O stretch and Si-N peaks depended on the annealing atmosphere as well as the annealing temperature. The intensity of Si-O peaks increased in the samples annealed in oxygen atmosphere, but it decreased in the samples annealed in nitrogen atmosphere. The intensity of Si-N peak decreased in the samples annealed in oxygen atmosphere, but it increased in the samples annealed in nitrogen atmosphere. The position of Si-O peaks shifted from 1030 nm to 1140 nm in the samples annealed both in oxygen and in nitrogen atmosphere. It was also observed that the intensities of Si-H (∼2250 cm−1) and N-H (∼3550 cm−1) peaks decreased apparently as the annealing temperature increased in all annealed samples.

Kinetics of Chemical Vapor Deposition of Sic Between 750 and 850°C at 1 Bar Total Pressure

1991 ◽  
Vol 250 ◽  
Author(s):  
Dieter Neuschütz ◽  
Farzin Salehomoum
Keyword(s):  
Deposition Rate ◽  
Total Pressure ◽  
Reaction Rate ◽  
Chemical Vapor ◽  
Deposition Mechanism ◽  
Reaction Orders ◽  
Si Content ◽  
Boundary Reaction ◽  
Phase Boundary Reaction ◽  
Kinetics Of

AbstractThe deposition rate from mixtures of methyltrichlorosilane (MTS), hydrogen and methane was measured thermogravimetrically using a hot wall vertical reactor and planar SiC substrates. Below 850 °C and at sufficiently high gas velocities, the rate of the phase boundary reaction could be determined. In the absence of CH4 and at H2 :MTS=55, Si was deposited together with SiC. Addition of CH4 lowered the Si content, pure SiC being deposited at CH4 :MTS above 10. The deposition rate j in the range 750 to 850 °C follows the equation with E(Si) = 160 and E(SiC) = 300 kJ/mol. Reaction mechanisms are presented to account for the observed reaction orders with respect to MTS. Between 900 and 970 °C, the reaction rate decreased with temperature indicating a change in the deposition mechanism.

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