06/13/2017

When it has to go fast: the FRT SLS

The FRT SLS is a fast optical line sensor for applications where high measuring speeds are required. Typical applications are the determination of 3D topography, step heights, roughness, flatness, as well as the structure and shape of samples.

It operates according to the principle of chromatic distance measurement. Instead of a single measuring spot, this sensor consists of 192 measuring spots arranged equidistantly along a line. A distance value with a vertical resolution in the nm range is generated for each measuring point. The chromatic effect is generated with the aid of special measuring heads, whose optical properties determine the z-measuring range of each measuring head. The measuring heads can be exchanged via a screw thread connection, making it possible to use the base sensor with different measuring heads and thus different measuring resolutions and ranges. This measuring method is suitable for highly reflective, rough or dark samples and can therefore be used for a wide range of applications. The line arrangement of the measurement points, makes it possible to directly produce a 3D measurement along the scan direction.

With measuring rates up to 2 kHz, the scanning of a sample takes a fraction of the time required for single point sensors – with data collection rates of up to 384.000 measured values ​​per second. For example, full bump measurement on a highly populated 12 inch wafer takes less than 20 minutes. Co-planarity, bump height and bump diameter are determined and output automatically. In comparison, the same measurement with a single CWL point sensor would take more than 2 days.

Use this sensor in a FRT multi-sensor MicroProf® tool.

Do not hesitate to contact us with any questions. Our experts will be glad to take care of your needs and work out individual solutions for you.