Oxygen Atom Induced Deposition of Silicon Dioxide

1992 ◽  
Vol 282 ◽  
Author(s):  
Dimitri A. Levedakis ◽  
Gregory B. Raupp
Keyword(s):  
Silicon Dioxide ◽  
Deposition Rate ◽  
Total Pressure ◽  
Oxygen Radical ◽  
Flow Ratio ◽  
One Dimensional ◽  
Substrate Temperatures ◽  
Oxygen Discharge ◽  
Deposited Films ◽  
Deposition Conditions

ABSTRACTSilicon dioxide was deposited from tetraethylorthosilicate (TEOS) and remote microwave oxygen plasma on a heated silicon substrate in a cold-wall reactor. The deposition rate and film quality were examined as functions of substrate temperature, total pressure, absorbed plasma power and O2:TEOS flow ratio. The deposition reaction exhibited an activation energy of approximately 10 kJ/mol for substrate temperatures in the range of 323–623 K. The deposition rate reached a maximum with increasing total pressure. The rate was found to be a near-linear function of the absorbed microwave power. At fixedabsorbed power the rate reached a maximum with increasing O2:TEOS flow ratio. A one-dimensional mathematical model was developed to predict the oxygen radical concentration at the exit of the afterglow region of the oxygen discharge. Comparisons of the predicted oxygen radical concentrations with the deposition rates at corresponding deposition conditions supports the view that the overall SiO2 deposition reaction is largely controlled by the concentration of oxygen radicals. The average refractive index ofthe deposited films was 1.466 ± 0.011. Fourier transform infra-red (FTIR) transmission spectra showed significant concentrations of hydroxyls in the deposited films.

Preparation of Boron Nitride Thin Films by MOCVD

1997 ◽  
Vol 495 ◽  
Author(s):  
Sang-Yeol Lee ◽  
Yong-Gi Jin ◽  
Young-Woo Nam ◽  
Joong Kee Lee ◽  
Dalkeun Park
Keyword(s):  
Thin Films ◽  
Boron Nitride ◽  
Partial Pressure ◽  
Deposition Rate ◽  
Total Pressure ◽  
Deposition Temperature ◽  
Operating Parameters ◽  
Film Characteristics ◽  
Deposited Films ◽  
Reactor Pressure

ABSTRACTBoron nitride thin films were prepared on Si(100) substrate by CVD. Triethylboron and ammonia were employed as precursors and various operating parameters such as reactor pressure, temperature, feed rates of gases were varied to investigate their effects on deposition rate and film characteristics. Total gas pressure in the reactor was varied from atmospheric to I torr. Deposition temperature was in the range 850 – 1,050 °C. Deposition rate increased with partial pressure of TEB but decreased with total pressure in the reactor. Deposited films were examined with SEM, FTIR, XPS, AES, XRD. Prepared films were BN of turbostratic structure.

Mechanism of Plasma-Enhanced Deposition of Silicon Dioxide from Teos/O2 Mixtures

1990 ◽  
Vol 204 ◽  
Author(s):  
Gregory B. Raupp ◽  
Timothy S. Cale ◽  
H. Peter ◽  
W. Hey
Keyword(s):  
Oxygen Atom ◽  
Silicon Dioxide ◽  
Deposition Rate ◽  
Total Pressure ◽  
Surface Recombination ◽  
Film Deposition ◽  
Rf Power ◽  
Atom Concentration ◽  
Wafer Temperature ◽  
Rate Determining Step

ABSTRACTThe deposition rate of silicon dioxide from TEOS/02 capacitively-coupled plasmas increases with increasing applied rf power, increasing total pressure and decreasing wafer temperature. These dependences can be explained by a mechanism in which deposition occurs through both an ionassisted and an oxygen atom initiated pathway. The ion-induced deposition rate increases with increasing rf power density and decreasing total pressure, and is independent of wafer temperature. Assuming a well-mixed plasma, and using literature values for reaction rate parameters and rate forms for oxygen plasma reactions, the rate of atom-induced deposition was found to be independent of temperature and TEOS concentration and directly proportional to oxygen atom concentration. The model suggests that the apparent negative activation energy for deposition results from competition between deposition and thermally-activated atomic oxygen surface recombination. The derived deposition rate form is consistent with an Eley-Rideal mechanism in which the rate determining step for film deposition is oxidative attack of adsorbed TEOS or TEOS fragments by a activated oxygen.

Characteristics of Polycrystalline Copper Films Made by CVD from Cu(HFA)2

1992 ◽  
Vol 260 ◽  
Author(s):  
Do-Heyoung Kim ◽  
Robert H. Wentorf ◽  
William N. Gill
Keyword(s):  
Growth Rate ◽  
Surface Roughness ◽  
Total Pressure ◽  
Deposition Time ◽  
Film Growth ◽  
Copper Films ◽  
Polycrystalline Copper ◽  
Grain Sizes ◽  
Substrate Temperatures ◽  
Deposition Conditions

ABSTRACTThin Copper films have been deposited on various substrates by the reduction of copper bis-hexafluoroacetylacetonate, Cu(HFA)2, with hydrogen to investigate the characteristics of the films made at 2–10 torr of total pressure, substrate temperatures of 280–400 °C and precursor temperatures of 55–90 °C. Under the conditions investigated, the highest growth rate was 650 Å/min. and the resistivity of the films was routinely near 2.0 μΩ-cm at 5000 Å or more thickness. Film growth rate depended on precursor concentration and substrate temperature. RBS and AES analysis indicate that the copper deposited at 310–400°C is highly pure. SEM photographs revealed that different structures form depending on substrate kind, the deposition conditions and the deposition time. The surface roughness of the films increased with increasing thickness. The reflectivity of the copper films depends on their thickness and decreases as the grain size increases. The grain sizes in the films were about 0.1–2.0 μm and are correlated with film thickness.

Reaction Mechanism for Deposition of Silicon Nitride by Hot-Wire CVD with Ultra High Deposition Rate(>7 nm/s)

2006 ◽  
Vol 910 ◽  
Author(s):  
Vasco Verlaan ◽  
Zomer Silvester Houweling ◽  
Karine van der Werf ◽  
Hanno D Goldbach ◽  
Ruud Schropp
Keyword(s):  
Silicon Nitride ◽  
Deposition Rate ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Good Control ◽  
High Deposition Rate ◽  
Flow Ratio ◽  
Hot Wire ◽  
Process Pressure ◽  
Deposited Films

AbstractThe deposition process of silicon nitride (SiNx) by hot-wire chemical vapor deposition (HW CVD) is investigated by exploring the effects of process pressure and gas-flow ratio on the composition of the deposited SiNx films. Furthermore, experiments with D2 and deuterated silane were performed to gain further insight in the deposition reactions taking place. It appeared that the N/Si ratio in the layers determines the structural properties of the deposited films and since the volume concentration of Si-atoms in the deposited films is constant with N/Si ratio, the structure of the films are largely determined by the quantity of incorporated nitrogen. Because the decomposition rate of the ammonia source gas is much smaller than that of silane, the properties of the SiNx layers are largely determined by the ability to decompose the ammonia and to incorporate nitrogen into the growing material. It appeared that the process pressure greatly enhances the efficiency of the ammonia decomposition, presumably caused by the higher partial pressure of atomic hydrogen. With this knowledge we increased the deposition rate to a very high value of 7 nm/s for dense transparent SiNx films, much faster than conventional deposition techniques for SiNx can offer. Despite this high deposition rate good control over the composition is achieved by varying the flow ratio of the source gasses. Depositions performed with deuterated silane as a source gas reveal that almost all hydrogen in N-rich films originates from ammonia, probably caused by SiNx matrix formation by cross linking reactions

(111) Monocrystalline Nickel Films

1972 ◽  
Vol 30 ◽  
pp. 512-513
Author(s):  
T.E. Pratt ◽  
R.W. Vook
Keyword(s):  
Film Thickness ◽  
Deposition Rate ◽  
Room Temperature ◽  
Narrow Range ◽  
High Vacuum ◽  
Residual Pressure ◽  
Temperature Dependent ◽  
Deposition Parameters ◽  
Transmission Electron ◽  
Substrate Temperatures

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.

Experimental assessment of the rotor outlet flow in a twin-entry radial turbine by means of Laser Doppler Anemometry

2021 ◽  
pp. 146808742110344
Author(s):  
José Galindo ◽  
Andrés Omar Tiseira ◽  
Luis Miguel García-Cuevas ◽  
Nicolás Medina
Keyword(s):  
Laser Doppler Anemometry ◽  
Effective Area ◽  
Laser Doppler ◽  
Flow Ratio ◽  
One Dimensional ◽  
Radial Turbine ◽  
Single Entry ◽  
Outlet Flow ◽  
Dimensional Models ◽  
Number Of Particles

The current paper presents the validation of some hypotheses used for developing a one-dimensional twin-entry turbine model with experimental measurements. A Laser Doppler Anemometry (LDA) technique has been used for measuring the axial Mach number and for counting the number of particles downstream of the rotor outlet. These measurements have been done for different mass flow ratio (MFR) and reduced turbocharger speed conditions. The flow coming from each turbine entry does not fully mix with the other within the rotor since, downstream of the rotor, they can still be differentiated. Thus, the hypothesis of studying twin-entry turbines as two separated single-entry turbines in one-dimensional models is corroborated. Moreover, the rotor outlet area corresponding to each flow branch has linear trends with the MFR value. Therefore, the rotor outlet effective area used for one-dimensional models should vary linearly with the MFR value.

Plasma Assisted Low Temperature OMVPE of GaAs Utilizing Trimethylgallium and Trimethylarsenic Feedstock Gases

1990 ◽  
Vol 201 ◽  
Author(s):  
B. G. Pihlstrom ◽  
L. R. Thompson ◽  
S. Asher ◽  
G. J. Collins
Keyword(s):  
Arrhenius Plot ◽  
Hydrogen Plasma ◽  
Transfer Reactions ◽  
Organometallic Vapor Phase Epitaxy ◽  
Kcal Mole ◽  
Homoepitaxial Growth ◽  
Surface Mobility ◽  
Diffraction Patterns ◽  
Substrate Temperatures ◽  
Deposited Films

AbstractA spatially confined disk shaped hydrogen plasma is used for plasma assisted organometallic vapor phase epitaxy (PAOMVPE) of GaAs at substrate temperatures from 245–430°C. Feedstock gases, trimethylgallium (TMGa) and trimethylarsenic (TMAs), are introduced downstream from the disk shaped plasma in the near afterglow. Dissociation of the organometallics is dominated by VUV photons and metastable species energy transfer reactions rather than non-selective electron impact. At the temperatures employed no thermal CVD occurs. An Arrhenius plot of the growth rate shows a low activation of 3 Kcal/mole for surface mobility. The transitional temperature from amorphous to homoepitaxial growth (300°C) is determined via electron diffraction patterns from deposited films versus substrate temperature. Increases in the feedstock gas V-III ratio resulted in decreases in absolute carbon concentration in the deposited films.

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.

Influence of Substrate Temperature on Some Properties of Close-Spacing Thermally Evaporated CdTe Thin Films

2008 ◽  
Vol 55-57 ◽  
pp. 881-884 ◽  
Author(s):  
Thitinai Gaewdang ◽  
N. Wongcharoen ◽  
P. Siribuddhaiwon ◽  
N. Promros
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Suitable Condition ◽  
Xrd Analysis ◽  
Thermal Evaporation Method ◽  
Cdte Thin Films ◽  
Influence Of Substrate ◽  
Substrate Temperatures ◽  
Deposited Films ◽  
Resistance Value

CdTe thin films with different substrate temperatures have been deposited by thermal evaporation method on glass substrate in vacuum chamber having low pressure about 3.0x10-5 mbar. According to XRD analysis, CdTe thin films are polycrystalline belonging to cubic structure with preferential orientation of (111) plane. The strongest peak intensity of XRD is observed in the film prepared with substrate temperature of 150°C. Band gap and band tail values of the as-deposited films were evaluated from the optical transmission spectra. The lowest dark sheet resistance value was obtained from the film prepared with substrate temperature of 150°C as well. Regarding to our experimental results, it may be indicated that the 150°C substrate temperature is the most suitable condition in preparing CdTe thin films for solar cell applications.

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