19 May 2008 Mask image position correction for double patterning lithography
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Proceedings Volume 7028, Photomask and Next-Generation Lithography Mask Technology XV; 70280D (2008) https://doi.org/10.1117/12.793021
Event: Photomask and NGL Mask Technology XV, 2008, Yokohama, Japan
Application of double patterning technique has been discussed for lithography of HP 3X nm device generation. In this case, overlay budget for lithography becomes so hard that it is difficult to achieve it with only improvement of photomask's position accuracy. One of the factors of overlay error will be induced by distortion of photomask after chucking on the mask stage of exposure tool, because photomasks are bended by the force of vacuum chucking. Recently, mask flatness prediction technique was developed. This technique is simulating the surface shape of mask when it is on the mask stage by using the flatness data of free-standing state blank and the information of mask chucking stage. To use this predicted flatness data, it is possible to predict a pattern position error after exposed and it is possible to correct it on the photomask. A blank supplier developed the flatness data transfer system to mask vender. Every blanks are distinguished individually by 2D barcode mark on blank which including serial number. The flatness data of each blank is linked with this serial number, and mask vender can use this serial number as a key code to mask flatness data. We developed mask image position correction system by using 2D barcode mark linked to predicted flatness data, and position accuracy assurance system for these masks. And with these systems, we made some masks actually.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Masato Saito, Masamitsu Itoh, Osamu Ikenaga, Kazutaka Ishigo, "Mask image position correction for double patterning lithography", Proc. SPIE 7028, Photomask and Next-Generation Lithography Mask Technology XV, 70280D (19 May 2008); doi: 10.1117/12.793021; https://doi.org/10.1117/12.793021

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