The accuracies of image placement and line-width on masks become very serious with continued reduction of design
rules in semiconductor device fabrication. Even a tiny deviation from the prescribed circumstances during a maskexposure
process can result in severe damage to masks and require re-works, and result in increased mask manufacturing
cost. In 2006, Mask Design, Drawing, and Inspection Technology Research Department (Mask D2I) at the Association
of Super-Advanced Electronics Technologies (ASET), launched a 4-year development program for the optimization of
mask design, drawing, and inspection to reduce the costs in photo-mask manufacturing.
We have developed a self-diagnostic technology to monitor the process of data transfer and check the environmental
condition during exposure to improve the reliability of the mask writer. The technology can improve the efficiency of
mask inspection if the deviation points are known prior to the inspection.
Our monitor and self-diagnostic system consists of a verification system for data processing, writing simulator, monitor
for circumstances, and integrated diagnostic system. Each part in the monitor and self-diagnostic system monitors and
diagnoses the status of data processing and circumstances.
We evaluated the reliability of monitoring the outer circumstances using an actual mask writing tool. The details and
results will be reported in this paper.