Ocean Optics NanoCalc - Manual (Page 66)

Ocean Optics Germany GmbH Thin Film Metrology
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10.1.5 Angle of incidence
“angle of incidence” is defined as the angle between the direction of incoming light and an axis vertical to the
surface.
In the current version of NanoCalc only vertical incidence is allowed.
10.1.6 Signal to noise ratio
The intensity of your acquired signal depends on:
the adjustment of the lamp (see light source or NanoCalc-2000 manual)
the integration time (see menu options)
the number of averages (see samples to average in menu options)
the diameter of the fiber
the distance between fiber and wafer
Do not extend the extraction limits into regions with a high signal-to-noise-ratio !
10.1.7 Stray light
Especially in a microscope setup there is a risk to catch stray light from your laboratory lamps. Try to avoid
this as much as possible or use the simple fiber setup. External light sources usually changes and will
produce errors.
10.1.8 Fiber
You may use different fibers with core diameters between 8 and 800 micrometers.
There are special fibers (Y-fibers, fibers with 6 outer fibers to illuminate and 1 inner fiber to detect the
reflected light, fiber cables for double spectrometers). In most cases it is easily possible to detect more or
less light through a different fiber constellation.
Consult your hardware supplier.
10.1.9 Absorbing media
It is not too easy to measure absorbing media like polycrystalline silicon as their refractive and absorption
indices usually depend strongly on preparation conditions.
Try to find good values of n(λ) and k(λ).
10.1.10 Passwords
There are several passwords within NanoCalc:
As a start for user mode and administrator mode there is a password “admin”. This password can be
changed.
To change intercept, first coefficient and second coefficient and third coefficient (to recalibrate your own
spectrometer) there is another password corresponding to the serial number of your Ocean Optics
spectrometer. This number is displayed on a separate sheet or on the backside of your spectrometer
system. If you could not find this serial number ask your hardware supplier…