Semiconductor

Optical scatterometry or optical critical dimension (OCD) is a common in-line metrology method for process control in semiconductor production. In addition to imaging techniques such as CD-SEM, OCD has developed as a fast, precise and non-destructive metrology, giving information about CD, height or side wall angles of the observed pattern structures. The relevant profile shape parameters are determined by illuminating a small area on the wafer under a certain angle and observing the scattered light via a spectrometer within the UV-NIR spectral range. To determine pattern profile information, model-based machine learning techniques are applied to wafer training spectra as a reference. ZEISS supplies OEM high-performance spectrometers like the  MCS-CCD  (190 - 980 nm)  or custom configurations for CD and overlay OCD-metrology.
High  end optical  plane gratings  enable you to measure cutting edge parameters in your metrology and are designed to specific customer requirements, such as the lowest levels of stray light, high efficiency and lowest wavefront aberration.

The production of semiconductor devices relies heavily on plasma etching processes. When patterns are etched on a wafer, the in-line control of etching progress is vital to avoid over and under-etch and ensure optimized process parameters, high yield and productivity. Optical metrology, such as optical emission spectroscopy (OES), spectral reflectometry (SR) and laser interferometry are common for plasma etch endpoint control. ZEISS  MCS-CCD (190 - 1015 nm) and CGS series (190 - 1100 nm) is ideal for optical emission spectroscopy where concentrations of plasma reactants are monitored during etching in real-time. MCS-CCD feature high resolution, broad spectral coverage, good wavelength accuracy and fast readout.  For spectral reflectometry the spectrometers of the MCS series  and CGS series  provide the required high dynamic range and good signal-to-noise ratio. ZEISS offers  plane gratings, which are used in single or multichannel spectrometers from VUV to NIR for customer-specific spectrometer developments for plasma monitoring and endpoint detection. Plane gratings with a wide range of line densities between 30{(-)}l/mm and 3600{(-)}l/mm provide well adapted resolution and signal-to-noise ratios due to the lowest levels of stray light.