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ISSN Online: 2377-424X

ISBN Print: 0-89116-909-1

International Heat Transfer Conference 9
August, 19-24, 1990 , Jerusalem, Israel

UNSTEADY CONVECTION IN CHANNEL FLOWS WITH APPLICATIONS TO CHEMICAL VAPOR DEPOSITION

Get access (open in a dialog) DOI: 10.1615/IHTC9.2500
pages 471-476

Abstract

Fabrication of micro-electronic circuits with chemical vapor deposition (CVD) depends critically upon the uniformity of the deposition processes which are strongly affected by convective and diffusive transport. A typical reactor configuration comprises a flowing gas in a channel with the deposition occurring on a heated substrate which forms a portion of the lower surface. The resulting mixed convection phenomena have been studied in an inclined channel reactor. We have solved the unsteady Navier-Stokes and energy equations and obtained results for the velocity and temperature distributions and local and average Nusselt numbers for a range of Reynolds and Grashof numbers and channel inclination angles, for both large and small temperature differences. Complex gas flow patterns occur as a result of transient thermal instabilities and strong accelerations. The Nusselt number varies significantly in both space and time; it increases with Grashof number, decreases for large temperature differences, and is from 2 to 5 times larger than the fully developed value. The effects of channel inclination and Reynolds number on the magnitude and periodicity of the Nusselt number are dependent in a complex manner on the parameters of the system. These results are important for the design and operation of CVD reactors as demands for uniformity become much more stringent.