A Character Size Optimization Technique for Throughput Enhancement of Character Projection Lithography

Abstract

Abstract-We propose a character size optimization technique to enhance the throughput of maskless lithography as well as photomask manufacture. The number of electron beam shots to draw the patterns of circuits is a dominant factor in the manufacture time and the cost for devices. Our technique is capable of drastically reducing them by optimizing the size of characters, which are the patterns to project and are placed on CP masks. Experimental results show that our technique reduced 72.0% of EB shots in the best case, comparing with the ad hoc character sizing.

Character Projection Lithography for Application-Specific Integrated Circuits

“…Cell library development methodologies were studied for character projection lithography (Sugihara et al, 2005, 2006a, 2006c, 2007b, 2008, 2010, Inanami et al, 2000. In this section, we focus on a cell library development methodology for a single-column-cell system (Sugihara et al, 2005(Sugihara et al, , 2006a(Sugihara et al, , 2006c(Sugihara et al, , 2007b. Cells, which are components for IC designs, are ordinarily utilized as the basis of characters.…”

“…Character size optimization techniques were studied for character projection (Sugihara, 2006c(Sugihara, , 2007b(Sugihara, , 2010. We first presented an idea to optimize a character size for higher projection throughput (Sugihara et al, 2006c).…”

“…We first presented an idea to optimize a character size for higher projection throughput (Sugihara et al, 2006c). We presented a character size optimization by enumerating all possible character sizes and generating a cell library for every given character size (Sugihara et al, 2006c).…”

“…We first presented an idea to optimize a character size for higher projection throughput (Sugihara et al, 2006c). We presented a character size optimization by enumerating all possible character sizes and generating a cell library for every given character size (Sugihara et al, 2006c). Next we presented a cell library development methodology in which a character size and a set of cells were optimized at the same time (Sugihara et al, 2007b).…”

“…We presented a character size optimization by enumerating all possible character sizes and generating a cell library for every given character size (Sugihara et al, 2006c). Next we presented a cell library development methodology in which a character size and a set of cells were optimized at the same time (Sugihara et al, 2007b). We also presented a character size optimization technique for multicolumn-cell projection equipment.…”