Thin film measurements for a wide variety of films


Instrument Performance

Automated Mapping

In Situ ALD



Film Sense Multi-Wavelength ellipsometers excel at measuring the thickness and index of refraction of transparent single films. The upper thickness limit depends on the ellipsometer system (typically 2 – 5 μm), but is also dependent on the substrate and film optical constants. As with any ellipsometer system, a minimum film thickness (typically 10 nm) is required to obtain accurate index of refraction measurements (the new Liquid Cell option can remove this limitation).

Optically absorbing films can also be measured, but the data analysis becomes more complicated as the film optical constants (both n and k values) are required. The Film Sense software contains multiple methods for determining n&k values: 1) multi-sample analysis, 2) combined ellipsometry + transmission measurements, 3) immersion ellipsometry with the new Liquid Cell option, and 4) dispersion models. The upper thickness limit for absorbing films is strongly dependent on the type of material; for metallic films, the upper limit is typically 50 nm.

Multi-Wavelength Ellipsometry can also be used to measure multilayer film stacks (in some cases up to 5 layers), depending on the thicknesses and indices of refraction of the layers. Simulations can be performed in the Film Sense software to determine if a particular sample structure is possible. For some samples, surface roughness and index gradients in the film can also be characterized.

Send Us Your Samples

As thin film measurement applications are so varied and diverse, the best way to determine if a Film Sense Multi-Wavelength Ellipsometer is right for your application is to perform demonstration measurements on your actual samples. Please contact us to discuss your application, and arrange for sample measurements.

Send Us Your Samples

As thin film measurement applications are so varied and diverse, the best way to determine if a Film Sense Multi-Wavelength Ellipsometer is right for your application is to perform demonstration measurements on your actual samples. Please contact us to discuss your application, and arrange for sample measurements.


The typical Film Sense ellipsometer thin film measurement Accuracy and Precision for a variety of samples, including a multi‐layer sample, is shown in the table below. For more details on the testing methodology, contact Film Sense and request our “FS‐8 Performance” white paper.

Click the Sample Type in the chart below to view examples:






0.013 nm

0.00026 nm


Index @ 633 nm

0.11 nm


0.00041 nm



Index @ 633 nm

0.60 nm


0.0038 nm


Top SiO2 Thickness

Si3N4 Thickness

Bottom SiO2 Thickness

SiO2 Index @ 633 nm

0.04 nm

0.08 nm

0.10 nm







Index @ 633 nm

0.002 nm


0.00030 nm



Index @ 633 nm

k @ 633 nm

0.042 nm



0.001 nm




Surface Roughness

Index @ 633 nm

k @ 633 nm

0.59 nm

0.004 nm



0.0036 nm

0.0011 nm




Surface Roughness

Index @ 633 nm

0.29 nm

0.12 nm


0.0031 nm

0.0012 nm



Oxide Thickness

Band Gap

0.08 nm

0.02 nm

0.0024 eV

0.0009 nm

0.00054 nm




0.042 nm

1.1 uOhm-cm

0.00047 nm

0.02 uOhm-cm


Thin Film Measurement Examples

Film Sense Automated Mapping Systems are fast, easy to operate, and can characterize thickness uniformity on wafers up to 300 mm in diameter.  Click on the buttons below for examples of thin film measurements from Film Sense Automated Mapping Systems.

“The system (FS-XY150) is great and we are having an increase of users using it. I am happy with the system and I direct users to use it when I am training them on our ALD deposition system. It gives great results and the customer support is quick and helpful too.”

– Tony Whipple, Scientist
Minnesota Nano Center

Film Sense

FS-1 Multi-Wavelength Ellipsometer

ALD In Situ Applications

Film Sense Multi-Wavelength Ellipsometers are ideal for Atomic Layer Deposition (ALD) applications.

  • The excellent thickness precision can easily resolve the sub-monolayer thickness changes for individual ALD cycles
  • The compact design simplifies the mounting and integration with ALD reactors for in situ thin film measurements
  • The in situ, real time thickness data provided by the FS-1 can significantly reduce the ALD process development time when exploring new process parameters and precursors
  • If in situ thin film measurements are not possible (ports on the ALD chamber are required to provide access for the optical beam), the FS-1 can still provide accurate ex situ thickness measurements for very thin ALD films, at an affordable price

Film Sense Ellipsometers have been installed for in situ thin film measurements on many different ALD reactors, including custom designs, commercial reactors, and on the applications below.


“These FS-1 ellipsometers are one of the best upgrades to our atomic layer processing reactors, and have now become an integral part of all our experiments on ALD and ALE.”

Dr. Sumit Agarwal – Colorado School of Mines

Click here to learn more about how Colorado School of Mines
is using Film Sense Ellipsometers as part of their research.

Thin Film Measurement

“The Film Sense FS-1 in situ ellipsometer has greatly facilitated data acquisition and understanding of the thin film deposition processes in our lab. The instrument was relatively easy to incorporate onto a vacuum chamber, and includes a user-friendly manual and tutorial to explain basic operation. With this tool, we are able to collect much more information during a deposition, including measurements between ALD half-cycles that are not feasible with ex situ techniques. These ellipsometers have become an integral part of our laboratory research, and we look forward to continuing to work with Film Sense in the future.”

Rachel Nye, PhD – student in Chemical Engineering
Parsons Research Group, North Carolina State University

Thin Film Measurement

“Overall performance, affordability and ease of use has made the FS-1 a workhorse for our ALD process as well as equipment development efforts.  The next generation FS-1EX provides a combination of higher beam intensity and wider spectral range improving both precision and accuracy.  For metallic thin films such as TiN, Pt and Ru, two additional IR wavelengths enhance the ability to monitor film thickness and resistivity in-situ during growth.  This enhanced performance helps us to streamline development efforts by effectively understanding the impact of different process conditions on film quality in real-time.”

Bruce Rayner​ – Principal Scientist
Atomic Layer Deposition, Kurt J. Lesker Company

Click here to learn more about how Kurt J. Lesker Company is using Film Sense Ellipsometers.

Thin Film Measurement

“The Film Sense FS-1 is a powerful and reliable tool for in-situ characterization of ALD films. The real-time dynamic thickness measurements were critical to understanding the growth characteristics of multicomponent oxides, such as lead zirconate-titanate (PZT), which I studied for my dissertation research through the University of Maryland. The in-situ thickness data I collected with the FS-1 allowed me to screen precursors much more quickly than if I had to rely on ex-situ characterization methods. I continuously used the FS-1 for over five years and haven’t experienced any downtime other than during occasional realignments when switching from ex-situ to in-situ measurement modes. The FS-1 would make a valuable addition to any laboratory looking to enhance their nondestructive thin-film thickness measurement capability.”

– Nicholas A Strnad, Ph. D.

Strnad, N. A. (2019). Atomic layer deposition of lead zirconate-titanate and other lead-based perovskites. (Doctoral Dissertation, University of Maryland Department of Materials Science and Engineering, College Park, USA).

Thin Film Measurement

“To summarize our nearly 5-year ownership experience of the FS-1 tool, all I can say, it’s most probably by far the highest performance/cost tool I have ever acquired in my independent research career. Besides the tool itself, as an ellipsometry expert, Film Sense has been very responsive to our data analysis/fit inquiries and saved us valuable research time by sharing his expertise. We are looking forward to getting their latest generation system with additional features that we can integrate for good on either of the reactors. Right now, our single FS-1 tool is going back-and-forth between thermal and plasma reactor based on our needs.”

– Necmi Biyikli, Assistant Professor,
Electrical and Computer Engineering, University of Connecticut

Click here to learn more about how University of Connecticut
is using Film Sense Ellipsometers
as part of their research..

Thin Film Measurement

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