Encyclopaedia Index

TITLE:  PHOENICS-CVD Example

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.

FLOW AND COMPUTATIONAL DETAILS

This is an idealised batch reactor for tungsten deposition; the chemistry is the same as the second example.

The reactor contains 12 wafers. As a simplifying option, it is possible to include fewer wafers and compensate for the reduced surface area.

The geometry and velocity vectors are shown below.

The geometry and velocity field.

The wafers are heated mainly by radiation from the outer wall.

Temperature Contours

The depletion caused by the surface reaction is apparent.

WF6 mass fraction

This is purely a product of the reaction on the wafer surface.

HF mass fraction

Although hydrogen is a reactant its mass fraction increases as the loss of tungsten reduces the mixture molar mass.

H2 mass fraction

Deposition on the wafer is fairly uniform except for the leading wafers in the batch which are cooled by the incoming gas.

Deposition rate