Olympus USPM-RU-W Series Operation Manual page 87

method
Layer
Film thickness analysis
The three ways below used to analyze a spectral reflection factor are provided as film
thickness analysis. Select an analysis method according to the application. The refractive
index of the coat materials may have to be set when calculating the physical and optical
film thickness. Set the refractive index on a LAYER setting window according to the table
below.
As the result of film thickness analysis, the calculated value varies depending on each
setting state. Use this function to obtain a relative value.
(1) Peak-valley method: [PV]
This method is used to calculate film thickness from the peak and valley periodicities of
the measured spectral reflection factor value data. Film thickness can be easily obtained
because a complicated setting is not required. This method is effective only for the
analysis of a single-layer film. However, this method cannot be used when two or more
peaks and valleys do not exist in the analysis range.Set the first layer's refractive index of
layer setting when obtaining the physical film thickness.
In the peak-valley method, the refractive index of the coat materials can be set using
[Use reflectance of substrate]. A data file for which the spectral reflection factor value of a
substrate was measured is specified for [Use reflectance of substrate]. Using the
expression below, the refractive index n
wavelength is obtained from the substrate's refractive index n
PV8959-F4E005
Sets the analysis method of the film thickness; [PV] is a
peak-valley method, and [FFT] is a frequency analysis
method. [FIT] is a curve fit method. For details of each
method, see the section below.
Enter the design parameters of a layer to be analyzed.
Setting is not required when the analysis method is [PV]
and when the unit is [Optical]. Excluding that described
above, set the following items:
When the unit is [Physical]
PV: Refractive index of the first layer
FFT: Refractive index of each layer not including the
AIR and SUBSTRATE layers
FIT: All items
When the unit is [Optical]
PV: Not required
FFT: Number of layers
FIT: All items
of the coat materials in the peak or valley
c
34
, converted from the
b