In Situ Monitoring

Realtime monitoring and control of thin film processes

Film Sense Multi-Wavelength Ellipsometers are ideal for in situ realtime monitoring and control of thin film deposition and etching processes. The ability to watch and characterize a process in realtime by in situ ellipsometry measurements can be extremely beneficial for diagnosing problems in a process chamber and improving the efficiency of process development.

In Situ Ellipsometer Capabilities

  • Sub-monolayer thickness precision
  • Determine film optical constants n&k and deposition rates, at multiple process conditions, without breaking vacuum
  • Monitor and control the deposition of multilayer film structures
  • FS-API interface for external software control (LabVIEW™ compatible)
  • Applicable to most thin film deposition and etching techniques: Sputtering, ALD, ALE, MBE, CVD, PLD, etc.

In Situ Ellipsometer Features

  • Completely self-contained system, with no external electronics box or fiber connections required
  • LED light sources and no moving parts detector, for robust and reliable operation, and fast measurements
  • Compact and light weight source and detector units (<1 kg each)
  • Optional adapters for mounting to standard 2.75” or 1.33” conflat flanges, with easy to adjust coarse and fine tilt stages
  • Powerful software features for visualizing and analyzing dynamic ellipsometric data

In Situ Ellipsometer Mounting Specifications

  • Adapters for mounting the Film Sense source and detector units to standard 2.75” or 1.33″ conflat vacuum flanges (windows not included)
  • Easy to adjust tilt stages for beam alignment
  • In situ applications are varied and diverse. Contact Film Sense for more detailed mounting specifications and 3D CAD files to help integrate Film Sense Ellipsometers with your process chamber.
In Situ Ellipsometer

FS-8 with Auto-Align option, on Kurt Lesker ALD Chamber

In Situ Ellipsometer

FS-1 Mounted on AJA Sputter Chamber

Here is a screenshot of Film Sense software monitoring thin film growth from in situ measurements. The screen on the right shows the analysis model used for measuring these films.

Film Sense software monitoring thin film growth from in situ measurements. The screen on the right shows the analysis model used for measuring these films. Click to Enlarge

Data courtesy of US Army Research Lab

Data courtesy of US Army Research Lab. Click to Enlarge

Application Examples

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


“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..

“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).

“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.

“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

“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.

Auto-Align Option

Automated alignment stages for in situ ellipsometry

  • Compact, motorized tilt stages, with simple cable connections (no external control boxes)
  • Full auto-align of the ellipsometer Source and Detector, and system calibration, in ≈ 10 seconds
  • Front alignment detector provides fast feedback for centering the beam on the detector aperture
  • Provides ±4.5º of tilt adjustment to accommodate sample and chamber ports mis-alignment
  • Especially useful for long in situ beam path lengths, where it can be difficult to “find” the beam by manually adjusting a tilt stage
  • Standard mounting flanges for 1.33” or 2.75” conflat flanges; holes provided for custom mounting
  • Available now, requires a Gen 3 Film Sense ellipsometer

Auto-Align Demonstration Video

In Situ Ellipsometer
In Situ Ellipsometer

Fast Mode

Ultra-fast dynamic ellipsometric measurements with excellent thickness precision

  • Study fast dynamic processes with sub-Å thickness precision
  • Instead of scanning all wavelengths, one or more wavelengths can be selected for ultra-fast measurements
  • Measurement period is 3.2 ms for 1 selected wavelength (with dark correction), and 1.7 ms with the “No Dark Correction” option (each additional selected wavelength adds 1.6 ms)
  • Data acquisition can be synchronized with an experiment using the FS-API for external software control. Dynamic data can be saved for post-deposition re-analysis.
  • Available now, requires a Gen 3 Film Sense ellipsometer and software version 3.0

Fast Mode set in the Dynamic Measurements screen

In Situ Ellipsometer

Typical Thickness Precision (nm)
(1-sigma standard deviation)

In Situ Ellipsometer

Dynamic Thickness Data, Native Oxide on Si
(300 mm beam path length)

In Situ Ellipsometer

Connect With Us