7 - 2
XTC/3 Operating Manual
6
Determine the new density value with the following equation:
[1]
where:
D
1
= Initial density setting
T
x
= Thickness reading on Cygnus
T
m
= Measured thickness
7
A quick check of the calculated density may be made by programming XTC/3
with the new density value and observing that the displayed thickness is equal
to the measured thickness, provided that XTC/3's thickness has not been
zeroed between the test deposition and entering the calculated density.
NOTE:
Slight adjustment of density may be necessary in order to
achieve T
x
= T
m
.
7.3 Determining Tooling
1
Place a test substrate in the system's substrate holder.
2
Make a short deposition and determine actual thickness.
3
Calculate tooling from the relationship:
[2]
where
T
m
= Actual thickness at substrate holder
T
x
= Thickness reading on Cygnus
TF
i
= Initial tooling factor
4
Round off percent tooling to the nearest 0.1%.
5
When entering this new value for tooling into the program, T
m
will equal T
x
if
calculations are done properly.
NOTE:
It is recommended that a minimum of three separate evaporations be
made when calibrating tooling. Variations in source distribution and other
system factors will contribute to slight thickness variations. An average
value tooling factor should be used for final calibration.
Density g cm
3
D
1
T
x
T
m
-------
=
Tooling (%)
TF
i
T
m
T
x
-------
=