The Utility of Laser Light Scattering in Assessing the Mixability of Reagents for Chemical Vapor Deposition

1993 ◽  
Vol 324 ◽  
Author(s):  
Bin Ni ◽  
Gene P. Reck ◽  
James W. Proscia
Keyword(s):  
Chemical Vapor Deposition ◽  
Light Scattering ◽  
Titanium Nitride ◽  
Tin Oxide ◽  
Vapor Deposition ◽  
Laser Light ◽  
Chemical Vapor ◽  
Reaction Chamber ◽  
Laser Light Scattering ◽  
Tin Oxide Films

AbstractThe premixability of reagents used in chemical vapor deposition reactors is important to insure that gas feed lines and nozzles do not become clogged with particulates during operation. Even if reactants are to be kept separate until introduced into a reaction chamber, it is desirable to limit the number of particles formed. A reactor which utilizes laser light scattering to monitor particulate formation when gaseous reagents are mixed is described. The reaction of tin (IV) chloride with water is commonly used to produce tin oxide films by chemical vapor deposition. It was found by the light scattering experiment that at temperatures above about 110°C the number of particulates formed is greatly reduced. Therefore, it would be most desirable that these reagents be mixed above this temperature when depositing tin oxide from this reaction. The reaction of titanium tetrachloride with various amine was also investigated by this method. This reaction has been demonstrated to produce titanium nitride above 450°C. For each case, it was observed that there was a temperature above which the number of particulates was significantly reduced. This temperature was always below the optimal temperature for producing titanium nitride films.

Visualization of Atmospheric Pressure Chemical Vapor Deposition and Powder Spray Pyrolysis by Laser Light Scattering

1994 ◽  
Vol 363 ◽  
Author(s):  
Limin Mao ◽  
Ogie Stewart ◽  
Gene P. Reck ◽  
James W. Proscia
Keyword(s):  
Chemical Vapor Deposition ◽  
Light Scattering ◽  
Spray Pyrolysis ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Laser Light ◽  
Chemical Vapor ◽  
Ambient Air ◽  
Laser Light Scattering ◽  
Pressure Chemical

AbstractAtmospheric Pressure Chemical Vapor Deposition (APCVD) and powder spray pyrolysis are both pyrolytic thin film deposition techniques that are used to coat glass with thin films at atmospheric pressure. In the present study, the fluid dynamics of each process was investigated by laser light scattering. For each system, a 193 nm ArF excimer laser pulsed at 7 Hz was used for the analysis. In the case of the APCVD reactor, the difference in Rayleigh scattering between helium injected in the reactor and ambient air was used to characterize the process. For the powder spray process, laser scattering off the sprayed powder was used. The effect of various parameters is discussed.

scholarly journals Low Temperature Atmospheric Pressure Chemical Vapor Deposition of Group 14 Oxide Films

1994 ◽  
Vol 343 ◽  
Author(s):  
David M. Hoffman ◽  
Lauren M. Atagi ◽  
Wei-Kan Chu ◽  
Jia-Rui Liu ◽  
Zongshuang Zheng ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Tin Oxide ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Oxide Films ◽  
Chemical Vapor ◽  
Elastic Recoil ◽  
Pressure Chemical ◽  
Quartz Substrates ◽  
Tin Oxide Films

ABSTRACTDepositions of high quality SiO2 and SnO2 films from the reaction of homoleptic amido precursors M(NMe2)4 (M = Si, Sn) and oxygen were carried out in an atmospheric pressure chemical vapor deposition reactor. The films were deposited on silicon, glass and quartz substrates at temperatures of 250 to 450 °C. The silicon dioxide films are stoichiometric (O/Si = 2.0) with less than 0.2 atom % C and 0.3 atom % N and have hydrogen contents of 9 ± 5 atom °. They are deposited with growth rates from 380 to 900 Å/min. The refractive indexes of the SiO2 films are 1.46, and infrared spectra show a possible Si-OH peak at 950 cm−1. X-Ray diffraction studies reveal that the SiO2 film deposited at 350°C is amorphous. The tin oxide films are stoichiometric (O/Sn = 2.0) and contain less than 0.8 atom % carbon, and 0.3 atom % N. No hydrogen was detected by elastic recoil spectroscopy. The band gap for the SnO2 films, as estimated from transmission spectra, is 3.9 eV. The resistivities of the tin oxide films are in the range 10−2 to 10−3 Ω cm and do not vary significantly with deposition temperature. The tin oxide film deposited at 350°C is crystalline cassitterite with some (101) orientation.

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