Ocean Optics ElliCalc - Manual (Page 16)

Ocean Optics Germany GmbH Thin Film Metrology
15
6.6 Continuous mode
The continuous button switches between continuous mode (=
red button) and “stop continuous” (button
=black). Then there will be a continuous measurement of the signal (necessary to adjust the height and tilt
of your stage !!)
All others buttons of ElliCalc are disabled until you finish the continuous mode.
6.7 Fitness
Any extraction of parameters is accompanied by a value of " fitness ". This is the sum of the mean square
deviations between measured and simulated curve (normalized to the range of extraction). The fitness is a
rough guide whether your thickness value is "good" or not.
In the file “Thinfilm.ini” you will find 3 entries in section [fit]:
Failure_RedLevel=1
Failure_YellowLevel=0.1
RYG_LevelsAreDisplayed=False
If you change the variable RYG_LevelsAreDisplayed from “False” to “True” (in main menu “Fitparameters”),
the usual rainbow pattern on the screen will disappear and a simple color will show up.
• If the fitness is below Failure_YellowLevel=0.1 you will see a GREEN color.
• If the fitness is between Failure_YellowLevel=0.1 and Failure_RedLevel=1 you will see a
YELLOW color.
• If the fitness is above Failure_RedLevel=0.1 you will see a RED color
Attention:
If you measure very thick layers (with a good correlation between maxima positions, but bad correlation
between signal heights) you may end up with high values of fitness, but nevertheless the thickness results
may be o.k.