- Fraunhofer ISE has developed a prototype laser processing system to scan large-wafer formats
- It claims this ‘novel’ concept can process wafers 10 to 20 times faster than with conventional galvanometer scanners
- MOEWE Optical Solutions GmbH has developed an ultra-fast polygon scanner for UV wavelengths for the prototype
- EdgeWave GmbH provided a UV laser to enable a high repetition rate of up to 10 MHz
The Fraunhofer Institute for Solar Energy Systems ISE has developed what it calls a ‘novel’ concept of laser processing system to speedily scan large-format wafers of M12 configuration. This is the 2nd prototype it has built, following the successful demonstration of the 1st prototype in 2022.
While the previous prototype had a throughput of over 15,000 wafers/hour, the latest machine uses UV light to process wafers 10 to 20 times faster than with conventional galvanometer scanners (see Fraunhofer ISE & Team Propose High Throughput Measure).
The demonstrator system processes wafer formats up to M12 (210 x 210 millimeters) and creates structures of less than 15 µm in size, a reduction of 30% compared to the structures realized in current systems based on UV wavelengths, it shared.
Laser processing is becoming a challenge for equipment manufacturers as the industry moves towards large-wafer formats, since they need to ensure the same quality and cycle rate as conventionally sized solar cells.
Fraunhofer says the demonstrator system’s design allows very fine structures to be created on large work pieces at a very high cycle rate. It uses an ultra-fast polygon scanner for UV wavelengths, developed by its industrial partner MOEWE Optical Solutions GmbH, with a line frequency of up to 1,800 lines/second.
Another industrial partner EdgeWave GmbH contributed with a UV laser to enable a high repetition rate of up to 10 MHz with a maximum pulse energy of 5.6 µJ and completely arbitrary pulse sequences.
Fraunhofer ISE then integrated these with high-end optics, a linear stage and a beam guidance to complete the system.
Currently, the new laser processing system is being used to test new process regimes and determine the increase in throughput. The team said it plans to continue to work on addressing synchronization and absolute accuracies of the system components.
