Thin Film Metrology


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SENTECH Thin Film Metrology

We supply thin film metrology systems from Sentech Instruments of Berlin Germany. Our thin film metrology instruments use spectroscopic ellipsometry, laser ellipsometry and reflectometry to measure thin film properties such as thickness, refractive index, and other useful properties.

Spectroscopic Ellipsometers - spectral range 190nm (DUV) - 25µm (IR)

The SENresearch ellipsometer family makes use of both spectroscopy techniques and the step scan analyser principle for detection and offers the widest spectral range ellipsometry, the highest resolution, and best signal-to-noise ratio. The big advantage of multiplex detection is speed, by this making the SENresearch ellipsometers the fastest and most flexible ellipsometers available.

To fulfil the high requirements of our customers SENTECH improved the SENresearch FTIR ellipsometer to measure faster in the NIR, offering highest spectral resolution and widest spectral range with excellent signal-to-noise-ratio in shorter measurement time. SENresearch spectroscopic ellipsometers measure more than 1000 pairs of (Ψ, Δ) between 240-2500 nm in less than 10 s applying ultrafast FTIR spectroscopic ellipsometry.

This means 10 times faster measurements compared to state of the art solutions. In addition to increasing measurement speed, we have expanded the spectral range as far as 2500 nm. The lower limits are 190 nm with Deuterium-Halogen light source and MgF2 optics, 240 nm with Deuterium-Halogen light source and quartz optics, and 380 nm with Halogen light source.

Measurement of:

  • thin film thickness
  • refractive index
  • extinction coefficient
  • reflection
  • transmission
  • anisotropy
  • depolarization
  • scattering (Mueller matrix)
  • surface and interface roughness
  • lateral and vertical material non-uniformities
  • crystal modification
  • composition
  • impurities
  • orientation of organic molecules
  • conductivity
  • doping profiles

Applications:

  • optical coatings
  • coatings on glass
  • thin film solar cells
  • crystalline solar cells
  • single films and layer stacks
  • dielectric films
  • thin metallic films
  • semiconductor films
  • organic films
  • bulk materials
Wide Spectral Range

Laser Ellipsometers - Single Wavelength, High Speed

Highly accurate reference tools for refractive index and film thickness.

Measurement of:

  • thin film thickness
  • refractive index
  • extinction coefficient

Applications:

  • anti-reflective (AR) coatings for crystalline silicon solar cells
  • single films
  • dielectric films
  • thin organic films
  • native oxides
  • double layer stacks
  • bulk materials
Laser Ellipsometer

Reflectometers - spectral range 200nm (DUV) - 2.5µm (IR)

The spectroscopic reflectometers RM 1000 and RM 2000 measure reflectance of flat or curved samples with smooth or rough surface. Thickness, extinction coefficient, and refractive index of single films or layer stacks are calculated using SENTECH FTPadv Expert software. Single films between 5 nm and 50 µm thickness, layer stacks, and substrates can be analyzed in the UV‑VIS‑NIR spectral range.

The RM 1000 and RM 2000 represent high end SENTECH reflectometers. The table top device comprises the highly stabilized light source, the reflection optics with auto-collimating telescope and microscope, the height and tilt adjustable sample platform, the spectral photometer, and the power supply. It can be optionally equipped with an x‑y mapping stage and mapping software, objective lens for a second spot size, and a video camera.

Besides film thickness and optical constants, the composition of films (e. g. of AlGaN on GaN, SiGe on Si), AR coating (e. g. on textured silicon solar cells, UV sensitive GaN devices), and coatings on small medical stents can be measured by our reflectometers. These reflectometers support applications in microelectronics, microsystems technology, optoelectronics, glass coatings, flat panel technology, life science, biotechnology, and others.

Measurement of:

  • reflectance
  • film thickness
  • extinction coefficient
  • refractive index
  • non-uniformity of films on large area samples

Applications:

  • photoresists
  • dielectric hard masks
  • organic passivation layers
  • optical filters
  • anti-reflective (AR) coatings
  • coatings on flat or curved samples with smooth or rough surface
  • coatings on medical stents
  • membranes
  • air gap in LCD applications
RM1000 Reflectometer