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The laser lithography tool has been employed as a reticle writer, and has come to the front for advanced reticle fabrication since its second generation system of CORE-2564 TM was delivered to the industry in 1992. (Figure la). Resist for i-line wafer fabrication is available for the reticle writer, as it is utilizing a light source of Ar laser (363.8nm). With the laser writer, as the standard resist, OCG-895i IM is the most popular one so far in leading edge 6" square and 250 mils thick (6025 ) reticle fabrication to USA and Europe and THMR-iPl700 TM was introduced to Japan and Asia. (Figure ib). In order to meet requirements for advanced reticle fabrication in critical dimension (CD) performance, CD error sources due to blanks should be confined to a minimum, so that blanks enhancement is much more desired. Several strategies have been proposed to reduce the CD error sources, and one is to optimize resist coating process condition. We at HOYA had accomplished 895i coating process optimization in pre-coating treatment, coating thickness, post-spin baking (PSB), and reported in SPIE Vol. 25 12-04, 2621-09, and so on. We released such blanks to the industry in 1995, and its practical value has been appreciated by the blanks users so far. Another one is to look for and utilize an alternative resist, which has better process latitude. We have been evaluating THMR-iP3000 ' series if it could be a replacement resist over the present standard OCG-895i and iPl700. In this paper, we will report comparative evaluation results of THMR-iP3600 TM as a replacement resist of the present standard OCG-895i and THMR-iPl700. This study was done as preliminary one by a leading-edge i-line stepper of NSR-22O5il2D '' modified for 6025 reticle fabrication, instead of an actual laser writer, for our convenience on experimental study. We will also report our study results of iP3600 development condition optimization results to expand the process latitude.
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