APPLICATION: THIN FILM APPLICATIONS
In order to keep the thin film solar cell production stable, the adequate control of the layer deposition and treatment processes is crucial. Semilab offers several metrology solutions for the characterization of electrical and optical properties of the thin layers.
Our special design Four-Point-Probe and Eddy Current sensors provide accurate measurement of the sheet resistance of thin semiconductor, TCO or even metal layers in the total range of interest.
Using Semilab’s „Spectroscopic Ellipsometry” and „Spectroscopic Haze and Reflectance” techniques the complete characterization of the layer thickness and other optical parameters can be accomplished even on multilayer structures.
TECHNOLOGY: SPECTROSCOPIC ELLIPSOMETRY
In the semiconductor industry, there is continuous demand for higher performance and denser integrated circuits. These requirements push the advancement of technology which requires solving of manufacturing challenges. A key to success is to understand the chemical, mechanical and physical properties of wide range of materials used in a typical integrated circuit.
The µSE tool is designed to measure thin film thickness and optical properties inside a <50µm test pad on semiconductor product wafers. The applied measurement technique for obtaining these parameters in a high accuracy and repeatable way is spectroscopic ellipsometry. The μSE tool uses optimized spectroscopic ellipsometer (SE) arms and optics for the measurement inside small boxes of patterned Si wafers.
Ellipsometry measures the phase of the reflected light from the sample, therefore it is relatively insensitive for intensity fluctuations. The raw measurement data represent the complex information from the layer stack which then need to be modeled optically. The measurement results are obtained through numerical regression process of the model data to the raw measurement spectrum.
TYPICAL SE REGRESSIONS:
- Non-destructive optical technique, based on measurement of the change of the polarisation state of light after reflection at non normal incidence on the surface to study.
- It is a higly sensitive even for layer thickness below 5 nm
- Extremely versatile technique: it gives acccess to numerous parameters which characterize multilayer structures (eg. layer thickness, refractive index, absorption, porosity).
- Spectroscopic Ellipsometry for thin film thickness and optical functions, including complex multilayer structures
- Generalized Ellipsometry for Anisotropic materials/li>
- Transmission Ellipsometry for transparent substrates
- Scatterometry vs. wavelength and angle of incidence
- Mueller Matrix (11 or 16 elements) uniquely offered in combination with Scatterometry for 3D anisotropic materials
- Jones Matrix for simple anisotropic materials
- Reflectance & Transmittance vs. wavelength and incidence angle
- Porosimetry: Measurements of pore size and porosity in thin films
- In-situ measurement mode for real time control during deposition or etch process
- Mapping stage (X, Y, Z, rotation), manual or automatic
- Microspot (400 μm standard and 60 x 240 μm ultra small -customization subject to discussion)
- Environmental cells: cryostat, liquid cell, cooling and heating sample stage cells, QCM cell
- Atmospheric porosimetry chamber
- Visualization camera
- Spectroscopic reflectometer
- Extended spectral range detection
- Possibility of integration of other Semilab metrologies (4pp, Eddy, etc.)
Find out more on the Semilab website