Thin-Films in Integrated Circuits
Microspectrophotometers for Thin-Film Thickness
Thin-Film Thickness Measurements on Transparent
and Obaque Substrates
Technologies is the worlds leading developer of UV-visible-NIR
range scientific instruments for microanalysis. These include the QDI series
UV-visible-NIR microspectrophotometer instruments designed to help you
non-destructively measure the optical properties of microscopic samples. CRAIC's UVM series
microscopes cover the UV, visible and NIR range and help you analyze with
sub-micron resolutions far beyond the visible range. CRAIC
Technologies also has the CTR series Raman
microspectrometer for non-destructive analysis of microscopic samples. And
don't forget that CRAIC proudly backs our microspectrometer and microscope products with unmatched
service and support.
Thin-Films in Integrated Circuits
Modern integrated circuits are made by depositing layers of different
materials upon substrates and then etching circuits within those films. The
thickness of the films must be precisely controlled in order to reproducibly
manufacturer the integrated circuits that so much of our lives depend on.
Commonly, the films are only tens of nanometers thick and have circuit
dimensions in the sub-micron range.
Microspectrophotometers for Thin-Film Thickness Measurement
As such, microspectrophotometers, such as those manufactured by CRAIC
Technologies, are one of the most effective tools to quickly, easily and
reliably measure film thickness. Such film thickness measurement tools are
designed to seamlessly integrate the microspectrophotometer with sophisticated software and
automation in order to measure thin film thickness of sampling areas that can be
smaller than a micron across. Such instruments are designed to measure film
thickness of many types of films deposited upon many types of substrates.
Thin-Film Thickness Measurements on Transparent and Obaque Substrates
Film thickness measurements can be made on both transparent and opaque
substrates which enables such tools to be used to monitor film thicknesses on
such devices as flat panel displays in addition to semiconductor chips and MEMS
Figure 1 is an example of an integrated circuit as seen through a CRAIC Technologies
microspectrophotometer. The black square is the entrance aperture of the
spectrophotometer itself. Light passing through that aperture is measured in
terms of intensity versus wavelength. As one commonly sees with such thin films
as oil on water, the result is an interference pattern whose peak locations are
determined by a number of factors…including the thickness of the film. Figure 2
is one such example.
Figure 1. Integrated circuit as seen through
a CRAIC Technologies microspectrophotometer
These three reflectance spectra are of three different thicknesses of silicon
dioxide film deposited on a silicon substrate. Using these spectra, the QDI FilmPro™ software
then models the thicknesses of each of the layers using a number of sophisticated
algorithms. The results show that the red spectrum has a thickness of 10.1 nanometers,
the blue a thickness of 30.0 nanometers and the green a measured thickness of
50.0 nanometers. This same technique can be used to measure film thickness by
either transmission or reflectance of many types of materials and substrates.
And due to the flexibility of the CRAIC Technologies
thin film thickness measurement solutions, sampling areas can range from over
100 microns across to sub-micron.
Figure 2. Reflectance Spectra of Three Different Thicknesses
of Silicon Dioxide Film Deposited on Silicon Substrate
Source: CRAIC Technologies.
For more information on this source please visit CRAIC