Flow Regimes and Transitions in a Rapid Chemical Vapor Deposition Reactor Using Flow Visualization and Rayleigh Light Scattering

2000 ◽  
Author(s):  
Angelo G. Mathews ◽  
Jill E. Peterson
Keyword(s):  
Light Scattering ◽  
Flow Visualization ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Flow Regimes ◽  
Rayleigh Light Scattering ◽  
Flow Visualizations ◽  
Transition Points ◽  
Stable Flow ◽  
Rayleigh Light

Abstract Previous study of carrier gas flow in rapid chemical vapor deposition (RCVD) reactors has been limited mostly to numerical simulations and flow visualizations. In the present work flow regimes were observed and temperatures were measured in a vertical axisymmetric pedestal RCVD reactor using flow visualization and Rayleigh light scattering (RLS) for noninvasive temperature measurement. Flow visualizations revealed that the flow undergoes complex transitions between stable flow regimes as heating occurs. The two dominant stable flow regimes were buoyant stable (BS) and momentum stable (MS). RLS was used to determine the instantaneous carrier gas temperature at discrete points in the test section. The flow regimes and their transition points were easily recognized and agreed with flow visualization data. The flow visualizations and RLS tests showed identifiable trends in transition points between flow regimes and in the types of regimes encountered. These trends were dependent on Grashof number and Reynolds number.

Rayleigh Light Scattering Measurements of Transient Gas Temperature in a Rapid Chemical Vapor Deposition Reactor

1999 ◽  
Vol 122 (1) ◽  
pp. 165-170 ◽  
Author(s):  
J. F. Horton ◽  
J. E. Peterson
Keyword(s):  
Chemical Vapor Deposition ◽  
Light Scattering ◽  
Flow Field ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Gas Temperature ◽  
Wafer Temperature ◽  
Carrier Gas ◽  
Rayleigh Light Scattering ◽  
Rayleigh Light

A laser-induced Rayleigh light scattering (RLS) system was used to measure transient gas temperatures in a simulated rapid chemical vapor deposition (RCVD) reactor. The test section geometry was an axisymmetric jet of carrier gas directed down, impinging on a heated wafer surface. RLS was used to measure instantaneous gas temperature at several locations above the wafer as it was heated from room temperature to 475 K. Gas flow rate and wafer temperature correspond to jet Reynolds number Rei=60, wafer maximum Grashof number GrH=4.4×106, and maximum mixed convection parameter GrH/Rei2=1200; all conditions typical of impinging jet reactors common in the numerical literature. Uncertainty of RLS transient temperature from a propagated error analysis was ±2–4 K. Peak gas temperature fluctuations were large (in the order of 25 to 75 °C). Both flow visualization and RLS measurements showed that the flow field was momentum dominated prior to heating initiation, but became unstable by GrH/Rei2=5. It then consisted of buoyancy-induced plumes and recirculations. Up to the peak wafer temperature, the flow field continued to be highly three-dimensional, unsteady, and dominated by buoyancy. RLS measurements are shown to provide information on carrier gas instantaneous temperature and flow field stability, both critical issues in RCVD processing. [S0022-1481(00)02401-4]

Collision induced hyper-Rayleigh light scattering in CCl4

1996 ◽  
Vol 88 (3) ◽  
pp. 683-691 ◽  
Author(s):  
P. KAATZ ◽  
D.P. SHELTON
Keyword(s):  
Light Scattering ◽  
Rayleigh Light Scattering ◽  
Rayleigh Light

Depolarized interaction-induced Rayleigh light scattering in gaseous SO2

1999 ◽  
Vol 96 (6) ◽  
pp. 921-925 ◽  
Author(s):  
VINCENT W. COULING ◽  
CLIVE GRAHAM ◽  
JEAN M. MCKENZIE
Keyword(s):  
Light Scattering ◽  
Rayleigh Light Scattering ◽  
Rayleigh Light
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