As EUV(Extreme Ultraviolet) Lithography has been delayed because of technical difficulties, ArF-immersion technology is continued to be utilized in the several future years. To progress constantly chip’s minimization and pattern shrink with ArF wavelength, the adoption of aggressive SRAF(Sub Resolution Assist Feature) is inevitable. This trend is giving the big challenge in Photomask industry such as pattern collapse, pattern wiggling and bending. Generally, the reduction of the resist thickness is being tried to solve these problems. But this approach has the limitation, because of depending on the margin of etch process. Additionally, finding appropriate resist must be evaluated by a variety of experiments for verifying the stability of the process. According to several papers, the main reason of pattern collapse is the unbalanced capillary force at drying step in develop process. The capillary stresses (σ) experienced by the resist can be described as shown in equation (1.1) and Figure 1[1].

Date Published: 8 October 2014
PDF: 9 pages
Proc. SPIE 9235, Photomask Technology 2014, 92351N (8 October 2014); doi: 10.1117/12.2066279

Published in SPIE Proceedings Vol. 9235:
Photomask Technology 2014
Paul W. Ackmann; Naoya Hayashi, Editor(s)