Investigation of an upflow cold-wall CVD reactor by gas phase Raman spectroscopy

The gas phase dynamics of an inverted, stagnation point flow CVD reactor were studied by both experiment and modeling. The axial centerline temperature profile in the reactor was measured by analysis of the rotational Raman spectra from the carrier gas (N or H ) as a function of the inlet flow velocity and the reactor aspect ratio. It was found that a larger temperature gradient 2 2 normal to the susceptor surface was obtained with higher gas flow velocity, larger aspect ratio, and the use of a N carrier gas. 2 A two-dimensional axisymmetric model with detailed heat transfer descriptions predicted the experimental data well. The validated model clearly demonstrates that recirculation flows are less likely in inverted reactor geometry. 2002 Elsevier Science B.V. All rights reserved.