Omega System Kalibrering
Strål X-Separation mätning och kalibrering
Micronic Laser Systems AB produces and develops machines for the photo mask production market. One of their products is the Omega machine which exposes photo masks using 5 laser beams simultaneously. It is important that the distance between the each laser beam, the x-separation, is the same. The x-separation is today measured by exposing a photo mask with a certain pattern and thereafter measured with a metrology system. This takes to much time and it is desired to find a faster method to measure the x-separation without loosing precision.The task for this master thesis is to improve an existing measurement method which uses a calibration mask. This method is very fast but the results are too noisy. The goal is to reduce the noise to 5nm which gives the same result as measurements on a photo mask. In order to achieve this, a new pattern has to be designed on the calibration mask and the software for the measurement has to be adapted to the new pattern and for measurements using 5 beams simultaneously. A concept for automatic adjustment of the x-separation should also be developed.The results are a new calibration mask pattern that is thinner, higher and inverted and a new measurement algorithm that handles measurements with several beams active at the same time. With the new measurement algorithm the measurements have a 3? of 6nm. Comparison with results from measurements on an exposed photo mask shows that there is a difference of about ±15nm in nominal focus between the two methods. The lens that controls the x-separation is mounted on a linear motor that automatically adjusts the x-separation.