PROCESS DESCRIPTION
P
ROCESS
M
ANUAL
4.1-9
•
The paddle is colder then the
wafers and the tube.
•
Insert temperature
stabilization step in the recipe
after ‘evacuate’ and/or ‘heat
up’ step.
Wafers are thick at the edges and
thin at the center.
•
Temperature is not
homogeneous within wafer.
•
Process pressure is too high.
•
Insert temperature
stabilization step in the recipe
after ‘boat in’ and/or ‘heat up’
step.
•
Decrease process pressure.
No consistency in uniformity.
•
Dirty quartz ware or wafers.
•
No constant pressure control.
•
Draft along the furnace.
•
Clean tube, quartz ware and
paddle.
•
Use clean wafers.
•
Check pressure control.
•
Decrease draft by reducing
overpressure cleanroom or
close possible draft holes.
Layer is too thin cross load.
•
Deposition time is too short.
•
Pressure is too low.
•
Increase deposition time in
recipe.
•
Increase pressure.
Layer is too thick cross load
•
Deposition time is too long.
•
Pressure is too high.
•
Decrease deposition time in
recipe.
•
Decrease pressure.
4.1.9
NH
4
Cl vapor pressure curve
