01/09/2018

Fully automated optical surface measurement opens up potential for your production

Inspection of incoming material, monitoring of individual production steps or quality assurance of finished products – optical surface measurement technology is becoming increasingly popular in production thanks to its fast, flexible and automated measurement procedures. The integration of optical surface measurement in production environments offers significant potential.

Especially in the high technology industry, the demands on the surfaces of materials are permanently increasing and the complexity of products is constantly growing. Solar technology, microelectronics or medical technology, to name just three areas, use surfaces as functional carriers, for example in terms of corrosion protection, biocompatibility, electrical conductivity or optical and haptic properties. Manufacturing processes such as joining, moulding and coating often take place in the micro- and nanometer range. If only minimal deviations in the sub-nanometer range have a significant impact on the functionality of a product – as in wafer technology, for example – a permanent monitoring of the production process and corresponding quality assurance is important for a company’s success. Precise and reliable characterization by means of control measurements is nowadays indispensable. Optical surface measurement, which is non-contact and thus non-destructive, has proven to be the perfect solution.

The more and more complex products such as solar cells, artificial knee joints, optical lenses or microelectronic components can only be inspected with a highly versatile measuring technique. A single method is not enough in such cases.

FRT multi-sensor measuring tools fulfill these requirements. They combine various measuring methods and sensors that allow a broad range of surface properties such as geometry or 3D topography to be measured with high precision. At wafer level, the manufacturers are interested in the characterization of roughness, total thickness variation (TTV), bow, waviness or the height and width of the electrical conductor paths. Here, multi-sensor measuring tools quickly provide important information about the ideal manufacturing parameters.

Automation in quality assurance includes two aspects: automation of the measurement process itself and integration into automated production processes. The former enables as many workers as possible to monitor product quality. One-button solutions have established themselves for this purpose: Automatic measuring programs for different procedures, parameters and ranges which the operator runs at the push of a button after placing the sample on the machine. With such solutions, even complex measurements on solar wafers are abstracted to understandable “good/bad evaluations”, for example. A second aspect of the automation in the measurement process is the positioning of the sample. Especially in the field of wafer technology, different handling and grabber systems can be used to simplify and accelerate the loading process. Powerful image acquisition hardware, intelligent pattern recognition, integrated calibration and automated measurement procedures ensure short throughput times and reliable results.

It is also important to integrate the results into production processes. In the semiconductor industry, for example, a powerful software platform of the measuring tools transfers the acquired information via a SEMI-compliant SECS/GEM interface to the next step in the production line. This also makes it easier to reduce material costs. This is an important advantage especially for expensive raw materials, such as those used in the solar industry. The industry is more and more trying to integrate optical 3D measuring technology directly into the production line (the so-called inline area) and thus enable 100% control of different parameters. This is for a good reason: An automated optical surface measurement ensures that measuring processes are reliable, fast, reproducible and verifiable. This means a development boost for quality assurance in production.

The MicroProf® MHU is completely integrated into the production workflow and fully automated. It offers all wafer manufacturers and the semiconductor industry the instrument to monitor production parameters and significantly improve quality. Thus, throughput and yield can also be increased. With its multi-cassette handling, the MicroProf® MHU is the instrument for fully automated wafer measurement. The tool inspects wafers with a diameter of 2” to 12” and measures the total thickness variation (TTV) of the samples as well as flatness, bow, warp, roughness, 3D topography and film thickness on both sides. The tool is mainly used for the processing steps sawing, grinding, lapping and polishing as well as for incoming inspection. Due to its extremely high accuracy and reproducibility, the MicroProf® MHU is suitable for the measurement of thin wafers, bonded and taped wafers made of silicon, sapphire, compound semiconductors, glass or quartz. A two-arm vacuum grabber automatically places the wafers from up to four cassettes at the measuring position. The end effector can be easily changed and adapted to wafer sizes from 2 to 12 inches (300 mm). The MicroProf® MHU can optionally be equipped with a wafer sorting system. The MicroProf® MHU can significantly increase the throughput, yield, precision and quality of your products.

We certainly have a solution for your specific task. Do not hesitate to contact us if you have any questions. Our experts will be glad to take care of your needs and work out individual solutions for you.