In the research, we describe a method that can well control the mean-to-target (MTT) difference in the critical dimension (CD) of the reticle. It is called the multi-etched (or re-etched) process, re-etched process will separate the conventional dry-etched process into two steps. The major purpose of the first etching is takeout the absorber layer and get preliminary CD results (line/width are less than but close to the design target), and the function of the second etched process (re-etched) can precisely control CD results to match design target. On the re-etched process, not only MTT difference but also CD uniformity will be improved. Therefore, the re-etched process might be a method to well control CD performance (i.e., MTT and uniformity) of the reticle for mask shop application.
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