TITLE:  PHOENICS-CVD Example 2

BY:      J R Heritage, CHAM Consultancy

DATE:  1996            PHOENICS Version:  2.2

PURPOSE OF CALCULATIONS:

To demonstrate the use of the CVD option in PHOENICS.

This is a showerhead reactor for tungsten deposition; the reactants are tungsten hexafluoride and hydrogen, with hydrofluoric acid as the product.

For this process the gas-phase chemistry is relatively unimportant and a single surface reaction is used.

The geometry and velocity vectors are shown below.

The inlet block is heated by radiation from the susceptor; it loses heat by radiation to the cooled outer walls and directly to the gas

H₂ is used up in the surface reaction but its mass fraction slightly increases as tungsten deposition reduces the mixture molecular mass

HF is created only at the susceptor surface and spreads throughout the reactor by convection and diffusion