[OPTICAL REVIEW Vol. 10, No. 5 (2003) 375-381]
© 2003 The Optical Society of Japan
Photomask Critical Dimension Metrology with Deep-Ultraviolet Microscope
Takeshi YAMANE and Takashi HIRANO
Mask Engineering Group, Semiconductor Company, Toshiba Corp., 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki 212-8583, Japan
(Received April 22, 2003; Accepted July 11, 2003)
A deep-ultraviolet (UV) microscope can output critical dimension (CD) that is consistent with an aerial image on a wafer even if the cross-sectional profile of the pattern on a photomask is varied. According to theoretical calculation, CD measured by the deep-UV microscope depends on global transmissivity, and so does the aerial image on a wafer if the cross-sectional profile is varied. The results of simulation and experiment indicate that offset between CD measured by deep-UV microscope and CD determined by the aerial image is constant despite variation of the cross-sectional profile.
Key words: photomask, critical dimension, metrology, deep-UV microscope, aerial image on wafer