Dépôt chimique en phase vapeur et à basse pression de couches minces à base de silicium dans un réacteur à lampes halogène

2000 ◽  
Vol 77 (9) ◽  
pp. 737-743
Author(s):  
B Semmache ◽  
S Kallel ◽  
H El Omari ◽  
M Lemiti ◽  
A Laugier
Keyword(s):  
Thin Films ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Environmental Safety ◽  
Device Fabrication ◽  
Process Time ◽  
Halogen Lamp ◽  
New Device ◽  
Si Films ◽  
Silicon Based

Low-pressure chemical vapor deposition (LPCVD) in halogen lamp-heated reactor (RTLPCVD: rapid thermal LPCVD) is a promising technique for silicon-based thin films deposition. Indeed, overall process time and gas consumption reduction in RTP reactors allows to project new device fabrication technologies (microsensors, solar cells) in order to reach a higher environmental safety with respect to classical technologies.Various gases available on our RTP installation (SiH4, NH3, N2O, O2, PH3, B2H6) enable several silicon-based thin films RTLPCVD deposition: intrinsic polycrystalline silicon (poly-Si) films or in situ doped poly-Si, silicon nitride (Si-N) and oxynitride (Si-O-N). In this paper, we discuss our results on deposition kinetics and physical properties of these thin films. It appeared that RTLPCVD silicon-based thin films with interesting structural, electrical, and optical properties can be synthesized in our lamp-heated reactor with a tight control of process parameters such as temperature, pressure, and gas flow ratios.

scholarly journals Improving the W Coating Uniformity by a COMSOL Model-Based CVD Parameter Study for Denser Wf/W Composites

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1089
Author(s):  
Leonard Raumann ◽  
Jan Willem Coenen ◽  
Johann Riesch ◽  
Yiran Mao ◽  
Daniel Schwalenberg ◽  
...  
Keyword(s):  
Relative Density ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Process Time ◽  
Parameter Study ◽  
Reactor Model ◽  
Production Route ◽  
Coating Uniformity ◽  
Hydrogen Retention ◽  
Return Lead

Tungsten (W) has the unique combination of excellent thermal properties, low sputter yield, low hydrogen retention, and acceptable activation. Therefore, W is presently the main candidate for the first wall and armor material for future fusion devices. However, its intrinsic brittleness and its embrittlement during operation bears the risk of a sudden and catastrophic component failure. As a countermeasure, tungsten fiber-reinforced tungsten (Wf/W) composites exhibiting extrinsic toughening are being developed. A possible Wf/W production route is chemical vapor deposition (CVD) by reducing WF6 with H2 on heated W fabrics. The challenge here is that the growing CVD-W can seal gaseous domains leading to strength reducing pores. In previous work, CVD models for Wf/W synthesis were developed with COMSOL Multiphysics and validated experimentally. In the present article, these models were applied to conduct a parameter study to optimize the coating uniformity, the relative density, the WF6 demand, and the process time. A low temperature and a low total pressure increase the process time, but in return lead to very uniform W layers at the micro and macro scales and thus to an optimized relative density of the Wf/W composite. High H2 and low WF6 gas flow rates lead to a slightly shorter process time and an improved coating uniformity as long as WF6 is not depleted, which can be avoided by applying the presented reactor model.

Effect of Nitrogen Doping on the Structure and Optical Properties of N-Type Hydrogenated Amorphous Silicon Thin Films

2011 ◽  
Vol 383-390 ◽  
pp. 6980-6985
Author(s):  
Mao Yang Wu ◽  
Wei Li ◽  
Jun Wei Fu ◽  
Yi Jiao Qiu ◽  
Ya Dong Jiang
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Amorphous Silicon ◽  
Photoelectron Spectroscopy ◽  
Gas Flow ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
Silicon Thin Films ◽  
Frequency Plasma ◽  
Hydrogenated Amorphous

Hydrogenated amorphous silicon (a-Si:H) thin films doped with both Phosphor and Nitrogen are deposited by ratio frequency plasma enhanced chemical vapor deposition (PECVD). The effect of gas flow rate of ammonia (FrNH3) on the composition, microstructure and optical properties of the films has been investigated by X-ray photoelectron spectroscopy, Raman spectroscopy and ellipsometric spectra, respectively. The results show that with the increase of FrNH3, Si-N bonds appear while the short-range order deteriorate in the films. Besides, the optical properties of N-doped n-type a-Si:H thin films can be easily controlled in a PECVD system.

Preparation of high-oriented molybdenum thin films using DC reactive magnetronsputtering

2017 ◽  
Vol 31 (07) ◽  
pp. 1750059 ◽  
Author(s):  
Zhengguo Shang ◽  
Dongling Li ◽  
She Yin ◽  
Shengqiang Wang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Roughness ◽  
Process Parameters ◽  
Gas Flow ◽  
Lattice Mismatch ◽  
Practical Significance ◽  
Process Time ◽  
Process Conditions ◽  
Influence Of Process Parameters

Since molybdenum (Mo) thin film has been used widely recently, it attracts plenty of attention, like it is a good candidate of back contact material for CuIn[Formula: see text]Ga[Formula: see text]Se[Formula: see text]S[Formula: see text] (CIGSeS) solar cells development; thanks to its more conductive and higher adhesive property. Besides, molybdenum thin film is an ideal material for aluminum nitride (AlN) thin film preparation and attributes to the tiny (−1.0%) lattice mismatch between Mo and AlN. As we know that the quality of Mo thin film is mainly dependent on process conditions, it brings a practical significance to study the influence of process parameters on Mo thin film properties. In this work, various sputtering conditions are employed to explore the feasibility of depositing a layer of molybdenum film with good quality by DC reactive magnetron sputtering. The influence of process parameters such as power, gas flow, substrate temperature and process time on the crystallinity and crystal orientation of Mo thin films is investigated. X-ray diffraction (XRD) measurements and atomic force microscope (AFM) are used to characterize the properties and surface roughness, respectively. According to comparative analysis on the results, process parameters are optimized. The full width at half maximum (FWHM) of the rocking curves of the (110) Mo is decreased to 2.7[Formula: see text], and the (110) Mo peaks reached [Formula: see text] counts. The grain size and the surface roughness have been measured as 20 Å and 3.8 nm, respectively, at 200[Formula: see text]C.

Effect of Various CF4/CH4 Flow Ratios on Structure and Optical Band Gap of Fluorinated Diamond-Like Carbon Thin Films

2010 ◽  
Vol 663-665 ◽  
pp. 312-315
Author(s):  
Jian Rong Xiao ◽  
Tao Tong ◽  
Yan Wei Li ◽  
Xin Hai Li
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Optical Band Gap ◽  
Chemical Vapor ◽  
Uniform Structure ◽  
Diamond Like Carbon ◽  
Radio Frequency Plasma ◽  
Frequency Plasma

Fluorinated diamond-like carbon (F-DLC) thin films are deposited using radio frequency plasma enhanced chemical vapor deposition under various gas flow ratios. The surface morphology of the F-DLC thin films deposited at lower gas flow ratios is a compact and uniform structure, and it became rough with the increase of gas flow ratios. The relative atomic contents of fluorine and chemical bonding configurations of C-Fx (x=1, 2, 3) in the thin films increases with the increase of gas flow ratios. The optical band gap of the thin films presents a decrease of different degree with the increase of gas flow ratios.

RuO2 films by metal-organic chemical vapor deposition

1993 ◽  
Vol 8 (10) ◽  
pp. 2644-2648 ◽  
Author(s):  
Jie Si ◽  
Seshu B. Desu
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Film Structure ◽  
Organic Chemical ◽  
Dilute Gas ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

Pure and conducting RuO2 thin films were successfully deposited on Si, SiO2/Si, and quartz substrates at temperatures as low as 550 °C by a hot wall metal-organic chemical vapor deposition (MOCVD). Bis(cyclopentadienyl)ruthenium, Ru(C5H5)2, was used as the precursor. An optimized MOCVD process for conducting RuO2 thin films was established. Film structure was dependent on MOCVD process parameters such as bubbler temperature, dilute gas flow rates, deposition temperature, and total pressure. Either pure RuO2, pure Ru, or a RuO2 + Ru mixture was obtained under different deposition conditions. As-deposited pure RuO2 films were specular, crack-free, and well adhered on the substrates. The Auger electron spectroscopy depth profile showed good composition uniformity across the bulk of the films. The MOCVD RuO2 thin films exhibited a resistivity as low as 60 μω-cm. In addition, the reflectance of RuO2 in the NIR region had a metallic character.

¼c Silicon Thin Films Deposited by Remote Plasma Enhanced Chemical Vapor Deposition Process

1990 ◽  
Vol 192 ◽  
Author(s):  
C. Wang ◽  
G. N. Parsons ◽  
S. S. Kim ◽  
E. C. Buehler ◽  
R. J. Nemanich ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Substrate Material ◽  
Degree Of Crystallinity ◽  
Silicon Thin Films ◽  
Hydrogen Dilution ◽  
Type C ◽  
Si Films ◽  
P Type

ABSTRACTIn an earlier study, we deposited ¼c-Si thin films by reactive magnetron sputtering (RMS). Here we extend our studies to the deposition of both undoped and high conductivity N-type and P-type ¼c-Si thin films by a remote PECVD. We show that ¼c-Si films can be deposited by bringing hydrogen, H2, into the source gas mixtures. The H2 could introduced by either upstream in a He/H2 mixture and directly plasma excited, or downstream, and be remotely excited along with the silane, SiH4, feed gas. The degree of crystallinity is shown to depend on the hydrogen dilution, the substrate temperature and the substrate material.

A Low Temperature Photonic Crystal Technology for Integration with Modern CMOS Technologies

2007 ◽  
Vol 990 ◽  
Author(s):  
Khadijeh Bayat ◽  
Mahdi Farrokh Baroughi ◽  
Sujeet K. Chaudhuri ◽  
Safieddin Safavi-Naeini
Keyword(s):  
Photonic Crystal ◽  
Low Temperature ◽  
Integrated Circuits ◽  
Gas Phase ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Silicon Oxynitride ◽  
Refractive Indices ◽  
Optical Integrated Circuits ◽  
Silicon Based

ABSTRACTIn this paper, low temperature amorphous silicon oxynitride (a-SixOyNz:H) thin film technology is proposed for implementation of CMOS compatible photonic crystal (PC) based optical integrated circuits (OICs). The a-SixOyNz films of different refractive indices were developed by plasma enhanced chemical vapor deposition (PECVD) technique using silane, nitrous oxide, and ammonia as gas phase precursors at 300°C. The films with refractive index between 1.43 − 1.75 were obtained by changing gas flow ratios. Such thin films can be used as cladding and core layers in photonic crystal structure.The bandgap and guiding properties of the a-SixOyNz based PCs were simulated and was shown that the a-SixOyNz:H based PC technology offers larger feature sizes than a conventional silicon based photonic crystals.

scholarly journals Postannealing Effect at Various Gas Ambients on Ohmic Contacts of Pt/ZnO Nanobilayers toward Ultraviolet Photodetectors

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Chung-Hua Chao ◽  
Mao-Yi Chen ◽  
Chii-Ruey Lin ◽  
Yueh-Chung Yu ◽  
Yeong-Der Yao ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Flow ◽  
Ohmic Contacts ◽  
Chemical Vapor ◽  
Rf Magnetron Sputtering ◽  
Zno Thin Films ◽  
Flow Rate Ratio ◽  
Silicon Substrates ◽  
Pt Electrode ◽  
Ultraviolet Photodetectors

This paper describes a fabrication and characterization of ultraviolet (UV) photodetectors based on Ohmic contacts using Pt electrode onto the epitaxial ZnO (0002) thin film. Plasma enhanced chemical vapor deposition (PECVD) system was employed to deposit ZnO (0002) thin films onto silicon substrates, and radio-frequency (RF) magnetron sputtering was used to deposit Pt top electrode onto the ZnO thin films. The as-deposited Pt/ZnO nanobilayer samples were then annealed at450∘Cin two different ambients (argon and nitrogen) to obtain optimal Ohmic contacts. The crystal structure, surface morphology, optical properties, and wettability of ZnO thin films were analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), photoluminescence (PL), UV-Vis-NIR spectrophotometer, and contact angle meter, respectively. Moreover, the photoconductivity of the Pt/ZnO nanobilayers was also investigated for UV photodetector application. The above results showed that the optimum ZnO sample was synthesized with gas flow rate ratio of 1 : 3 diethylzinc [DEZn, Zn(C2H5)2] to carbon dioxide (CO2) and then combined with Pt electrode annealed at450∘Cin argon ambient, exhibiting good crystallinity as well as UV photo responsibility.

Aerosol-Assisted CVD of SnO2 Thin Films for the Room-Temperature Detection of Hydrogen Sulfide

2013 ◽  
Vol 543 ◽  
pp. 422-425
Author(s):  
Huan Liu ◽  
Min Li ◽  
Jiu Xiao Wan ◽  
Jun Zhao ◽  
Qiu Yun Fu ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Flow ◽  
Room Temperature ◽  
Gas Sensing ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Temperature Detection ◽  
Low Concentrations ◽  
Initial Resistance ◽  
Deposition Conditions

High-quality SnO2 thin-film materials capable of detecting H2S gas of low concentrations at room temperature was demonstrated in this paper. We employed aerosol-assisted chemical vapor deposition process for the deposition of SnO2 thin films on alumina substrates with pre-patterned electrodes. The gas-sensing performances of the films prepared under different deposition conditions were systematically compared and analyzed. When SnCl2·2H2O was used as the precursor, a response sensitivity of 98.4 toward 50 ppm of H2S at room temperature was achieved. At room temperatures, the resistance upon the H2S gas exposure could recover to 90% of the initial resistance of the sensor when the H2S gas flow was turned off.

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