Characterization of Silicon-Nitride Film Growth by Remote Plasmaenhanced Chemical-Vapor Deposition (Rpecvd)

1993 ◽  
Vol 334 ◽  
Author(s):  
Zhong Lu ◽  
Yi Ma ◽  
Scott Habermehl ◽  
Gerry Lucovsky
Keyword(s):  
Gas Flow ◽  
Film Growth ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Nitride Film ◽  
Silicon Nitride Film ◽  
Flow Rates ◽  
Plasma Generation ◽  
Atom Source ◽  
Rate Ratios

AbstractWe have characterized RPECVD formation of Si-nitride films by relating the chemical bonding in the deposited films to the growth conditions. Gas flow rates for different N- and Si-atom source gases have been correlated with (i) the film stoichiometry, i.e., the Si/N ratio, and the (ii) the growth rate. N2 and NH3 were used as N-atom source gases, and were either delivered (i) up-stream through the plasmageneration tube, or (ii) down-stream. Different flow-rate ratios of NH3/SiH4 were found for deposition of stoichiometric Si-nitride films using up-stream or down-stream introduction of NH3. This is explained in terms of competition between excitation and recombination processes for the N-atom precursor species. Stoichiometric nitride films could not be obtained using the N2 source gas for (i) either up-stream or down-stream delivery, and (ii) for plasma powers up to 50 W. This is attributed to the higher relative binding energy of N-atoms in N2 compared to NH3, and to significant N-atom recombination at high N2 flow rates through the plasma generation region.

Numerical Investigation of Pulsed Chemical Vapor Deposition of Aluminum Nitride to Reduce Particle Formation

2011 ◽  
Author(s):  
Derek Endres ◽  
Sandip Mazumder
Keyword(s):  
Gas Phase ◽  
Direct Contact ◽  
Gas Flow ◽  
Film Growth ◽  
Chemical Vapor ◽  
Particle Formation ◽  
Group V ◽  
Flow Rates ◽  
Group Iii ◽  
Reactor Pressure

Particles of aluminum nitride (AlN) have been observed to form during epitaxial growth of AlN films by metal organic chemical vapor deposition (MOCVD). Particle formation is undesirable because particles do not contribute to the film growth, and are detrimental to the hydraulic system of the reactor. It is believed that particle formation is triggered by adducts that are formed when the group-III precursor, namely tri-methyl-aluminum (TMAl), and the group-V precursor, namely ammonia (NH3), come in direct contact in the gas-phase. Thus, one way to eliminate particle formation is to prevent the group-III and the group-V precursors from coming in direct contact at all in the gas-phase. In this article, pulsing of TMAl and NH3 is numerically investigated as a means to reduce AlN particle formation. The investigations are conducted using computational fluid dynamics (CFD) analysis with the inclusion of detailed chemical reaction mechanisms both in the gas-phase and at the surface. The CFD code is first validated for steady-state (non-pulsed) MOCVD of AlN against published data. Subsequently, it is exercised for pulsed MOCVD with various pulse widths, precursor gas flow rates, wafer temperature, and reactor pressure. It is found that in order to significantly reduce particle formation, the group-III and group-V precursors need to be separated by a carrier gas pulse, and the carrier gas pulse should be at least 5–6 times as long as the precursor gas pulses. The studies also reveal that with the same time-averaged precursor gas flow rates as steady injection (non-pulsed) conditions, pulsed MOCVD can result in higher film growth rates because the precursors are incorporated into the film, rather than being wasted as particles. The improvement in growth rate was noted for both horizontal and vertical reactors, and was found to be most pronounced for intermediate wafer temperature and intermediate reactor pressure.

Hydrogen Concentration Analysis in Pecvd and Rtcvd Silicon Nitride Thin Films and It's Impact on Device Performance

2001 ◽  
Vol 664 ◽  
Author(s):  
C. Y. Wang ◽  
E. H. Lim ◽  
H. Liu ◽  
J. L. Sudijono ◽  
T. C. Ang ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Threshold Voltage ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Gate Oxide ◽  
Nitride Film ◽  
Device Performance ◽  
Gas Flow Ratio ◽  
The Impact

ABSTRACTIn this paper the impact of the ESL (Etch Stop layer) nitride on the device performance especially the threshold voltage (Vt) has been studied. From SIMS analysis, it is found that different nitride gives different H concentration, [H] in the Gate oxide area, the higher [H] in the nitride film, the higher H in the Gate Oxide area and the lower the threshold voltage. It is also found that using TiSi instead of CoSi can help to stop the H from diffusing into Gate Oxide/channel area, resulting in a smaller threshold voltage drift for the device employed TiSi. Study to control the [H] in the nitride film is also carried out. In this paper, RBS, HFS and FTIR are used to analyze the composition changes of the SiN films prepared using Plasma enhanced Chemical Vapor deposition (PECVD), Rapid Thermal Chemical Vapor Deposition (RTCVD) with different process parameters. Gas flow ratio, RF power and temperature are found to be the key factors that affect the composition and the H concentration in the film. It is found that the nearer the SiN composition to stoichiometric Si3N4, the lower the [H] in SiN film because there is no excess silicon or nitrogen to be bonded with H. However the lowest [H] in the SiN film is limited by temperature. The higher the process temperature the lower the [H] can be obtained in the SiN film and the nearer the composition to stoichiometric Si3N4.

Microbridge Testing of Thin Films Under Small Deformation

1999 ◽  
Vol 594 ◽  
Author(s):  
T. Y. Zhang ◽  
Y. J. Su ◽  
C. F. Qian ◽  
M. H. Zhao ◽  
L. Q. Chen
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Silicon Nitride ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Chemical Vapor ◽  
Small Deformation ◽  
Nitride Film ◽  
Silicon Nitride Film ◽  
Pressure Chemical

AbstractThe present work proposes a novel microbridge testing method to simultaneously evaluate the Young's modulus, residual stress of thin films under small deformation. Theoretic analysis and finite element calculation are conducted on microbridge deformation to provide a closed formula of deflection versus load, considering both substrate deformation and residual stress in the film. Silicon nitride films fabricated by low pressure chemical vapor deposition on silicon substrates are tested to demonstrate the proposed method. The results show that the Young's modulus and residual stress for the annealed silicon nitride film are respectively 202 GPa and 334.9 MPa.

Preparation and Characterization of SiC Nanoparticles for ATF-FCM

2018 ◽  
Vol 281 ◽  
pp. 22-27
Author(s):  
Zhao Chen ◽  
Rong Zheng Liu ◽  
Jia Xing Chang ◽  
Ma Lin Liu
Keyword(s):  
Gas Flow ◽  
Chemical Vapor ◽  
Pure Hydrogen ◽  
Fukushima Accident ◽  
Flow Rates ◽  
Sic Nanoparticles ◽  
Hydrogen Flow ◽  
Different Temperatures ◽  
Carrier Gas Flow

Accident Tolerant fuel (ATF) concept was put forward after the Fukushima accident. Among different kinds of ATF, Fully Ceramic Microencapsulated Fuels (FCM) have been paid more and more attention in recent years. SiC matrix is one of the important constituent parts in FCM fuel system, which is sintered from kinds of SiC powders. In this study, SiC nanoparticles were prepared by Fluidized Bed Chemical Vapor Deposition (FB-CVD) method using Hexamethyldisilane (HMDS) as precursor, aimed at reducing the sintering temperature and pressure of FCM-SiC matrix. Experiments of different temperatures with different argon gas ratios were carried out. It was found that good crystal SiC could be obtained from 850°C to 1250°C, under pure hydrogen or H2: Ar=15:1. Different H2 carrier gas flow rate tests were also conducted. With the increase of hydrogen flow rates, the SiC was transformed from 3C-SiC to other types, such as 6H or 15R, but no significant effect was found on particle shape. Based on the characterizations of XRD, SEM and TEM, the results showed the spherical SiC nanoparticles could be obtained as well as 20 nanometers in diameter at the condition of 1150°C, H2: Ar=15:1, under different hydrogen flow rates. Different hydrogen flow rates had little influence on the particle size of SiC nanoparticles.

EFFECT OF ACETYLENE FLOW RATE ON ELECTROSORPTION CAPACITY OF CARBON NANOTUBE AND NANOFIBER COMPOSITE FILM ELECTRODES

2007 ◽  
Vol 14 (01) ◽  
pp. 135-139 ◽  
Author(s):  
X. Z. WANG ◽  
L. K. PAN ◽  
M. G. LI ◽  
Y. W. CHEN ◽  
R. M. CHENG ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Composite Film ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Nanofiber Composite ◽  
Spectra Analysis ◽  
Flow Rates ◽  
Hydrogen Flow ◽  
Successful Removal ◽  
Desalination Technology

Electrosorption of carbon nanotube and nanofiber (CNT–CNF) composite film electrodes was studied as a new desalination technology. The CNT–CNF composite film electrodes were grown on nickel sheets by low pressure thermal chemical vapor deposition. Different growth conditions at different acetylene flow rates of CNT–CNF composite film electrodes have been performed to obtain different crystallinities. The electrosorption experiments and Raman spectra analysis show the successful removal of ions with CNT–CNF composite film electrodes, depending on the optimal degree of crystalline perfection. In our work, optimal electrosorption was realized for the CNT–CNF composite film electrodes growing at 550°C with the acetylene and hydrogen flow rates of 30 and 200 sccm.

Novel Design of MOCVD Reactor with Three Radial Inward Flows for Epitaxial Growth of GaN Thin Films

2011 ◽  
Vol 308-310 ◽  
pp. 1037-1040
Author(s):  
Liao Qiao Yang ◽  
Jian Zheng Hu ◽  
Zun Miao Chen ◽  
Jian Hua Zhang ◽  
Alan G. Li
Keyword(s):  
Gas Flow ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Operating Pressure ◽  
Axisymmetric Mode ◽  
Mocvd Reactor ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
D Model

In this paper, a novel super large metal organic chemical vapor deposition (MOCVD) reactor with three inlets located on the periphery of reactor was proposed and numerical evaluation of growth conditions for GaN thin film was characterized. In this design, the converging effects of gas flow in the radial direction could counterbalance the dissipation of metal organics source. CFD was used for the mathematical solution of the fluid flow, temperature and concentration fields. A 2-D model utilizing axisymmetric mode to simulate the gas flow in a MOCVD has been developed. The growth of GaN films using TMGa as a precursor, hydrogen as carrier gas was investigated. The effects of flow rates, mass fraction of various species, operating pressure, and gravity were analyzed and discussed, respectively. The numerical simulation results show all the fields distributions were in an acceptable range.

Investigation of Thin Film Growth of B12As2 by Chemical Vapor Deposition

2003 ◽  
Vol 764 ◽  
Author(s):  
R. Nagarajan ◽  
J.H. Edgar ◽  
J. Pomeroy ◽  
M. Kuball ◽  
T. Aselage
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Thin Film Growth ◽  
X Ray Diffraction ◽  
Flow Rates ◽  
X Ray ◽  
Effects Of Temperature ◽  
Reactant Flow

AbstractThe chemical vapor deposition of icosahedral boron arsenide, B12As2, on 6H-SiC (0001) (on and off-axis) substrates was studied using hydrides as the reactants. The effects of temperature and reactant flow rates on the phases deposited and the crystal quality were determined. The growth rate increased with temperature from 1.5μm/h at 1100°C to 5 μm/h at 1400°C and decreased thereafter. X-ray diffraction revealed that the deposits were amorphous when the deposition temperature is below 1150° C. Above 1150°C, smooth B12As2 films were formed on 6H-SiC substrates with an orientation of (0001) B12As2 parallel to 6H-SiC (0001). Raman spectroscopy confirmed the strongly c-axis oriented nature of B12As2 film on 6H-SiC.

Characterization of Gan/Sapphire Interface and the Buffer Layer by TEM/AFM

2001 ◽  
Vol 7 (S2) ◽  
pp. 330-331
Author(s):  
B. Shea ◽  
Q. Sun-Paduano ◽  
D. F. Bliss ◽  
M. C. Callahan ◽  
C. Sung
Keyword(s):  
Buffer Layer ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Wide Band ◽  
Buffer Layers ◽  
Organic Chemical ◽  
Wide Band Gap ◽  
Tem Analysis ◽  
Flow Rates ◽  
Device Applications

Interest in wide band gap III-V nitride semiconductor devices is increasing for optoelectronic and microelectronic device applications. to ensure the highest quality, TEM analysis can characterize the substrate and buffer layer interface. Measurements taken by TEM reveal the density of dislocations/cm2 and the orientation of Burger's vectors. This information allows for changes to be made in deposition rates, temperatures, gas flow rates, and other parameters during the processing.The GaN/sapphire samples grown at AFRL were produced in two consecutive steps, first to provide a thin buffer layer, and the other to grow a lum thick epitaxial film. Both growth steps were prepared using metallic organic chemical vapor deposition (MOCVD) in a vertical reactor. Buffer layers were prepared using a range of temperatures from 525 to 535°C and with a range of flow rates and pressures in order to optimize the nucleation conditions for the epitaxial films.

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