Taylor Hobson launches Talysurf CCI SunStar

The SunStar features a 4 million pixel camera, film thickness measurement from 5 µm down to 300 nm, auto-range and auto-fringe-find, single mode of operation over all scan ranges and a closed loop Z scanning mechanism. One of the key application areas for Sunstar is PV Solar Cells. In first generation solar cells, produced using crystalline silicon, controlling the depth of scribe lines and the texture of the surface are important parts of the solar cell manufacture. The Talysurf CCI is able to handle these parameters in a single measurement. The roughness and trench depth can both be studied at the same time, because every measurement has sub nanometre resolution. Typically the whole measurement and analysis takes less than 1 minute to set up and measure (using auto-fringe find and auto-range). The average trench depth is the equivalent of over 2,000 stylus measurements and over 4 million data points are collected in each measurement. The large number of data points allows the study of surface roughness at the same time as the trench depth. The benefit of this multi analysis approach is that it speeds up the metrology involved in process control, making it more cost effective. In second generation solar cells, based on thin film semiconductor materials, it is possible to measure the thickness of semi transparent film coating when it is greater than 1-2 micrometres and less than about 20 micrometres using Thick Film analysis. The high z resolution of the Coherence Correlation Interferometry (CCI) technique makes it an ideal method for measuring these film thicknesses because of the sub nanometre resolution over this range. For films thinner than 1 to 2 micrometres a different approach has to be used. Taylor Hobson has released its film thickness software for measuring these thinner films on the CCI Sunstar interferometer. The CCI Sunstar is capable of measuring film thicknesses of semi transparent films from 5 µm down to 300 nm or less. The range of thickness that can be measured will vary from material to material depending on the optical properties of the film. The film thickness software is suitable for measuring many types of film including Cadmium Telluride (CdTe), and Copper Indium Gallium Diselenide (CIGS), Indium tin oxide (ITO), Zinc Oxide and Titanium Dioxide, which are often found in the solar cells.