Dehydration bake effects with UV/O3 treatment for 130-nm node PSM processing

As feature sizes of phase shift mask (PSM) have dropped below half-micron, resist adhesion have become a more critical issue, especially during second level lithography. Second writing process requires special consideration, because the resist's mechanical strength of resists on patterned chrome and patterned glass is smaller in comparison to that on the un-patterned chrome blank. If the adhesion strength is not sufficient to withstand the stress during subsequent processes, patterns will be damaged during second level lithography. Resists stress at pattern edges that subsequent processes, pattern will be damaged during second level lithography. Resist stress at pattern edges that weaken its adhesive property, together with the low mechanical strength of resists on glass, creates ample probability for the unwanted phenomenon in PSM process. In this paper, we investigate the effects of property and adhesive strength of resists on surfaces at different treatment before resist coating process, and observe the defects generation after different treatment.