Trefoil aberration measurement of lithographic projection optics based on linewidth asymmetry of the aerial image

The degradation of critical dimension uniformity caused by trefoil aberration of lithographic projection optics is a serious problem in the production of dynamic random access memory devices. In the present paper, we propose a novel method for measuring the trefoil aberration of lithographic projection optics. The trefoil aberration can be extracted from the linewidth asymmetry of the aerial image of brick-wall patterns. The present method has an advantage of timesaving. The test mark used in the present method is easy and cheap to fabricate, and the model for aberration extraction is simple. The PROLITH simulation results show that the trefoil aberration can be measured with high accuracy.

[1]  H. Nomura,et al.  Aberration measurement from specific photolithographic images: a different approach. , 2000, Applied optics.

[2]  Reiner Garreis,et al.  Impact of wavefront errors on low k1 processes at extremely high NA , 2003, SPIE Advanced Lithography.

[3]  Xiang-zhao Wang,et al.  Aberration measurement of projection optics in lithographic tools by use of an alternating phase-shifting mask. , 2006, Applied optics.

[4]  Jan B. van Schoot,et al.  Understanding systematic and random CD variations using predictive modeling techniques , 1999, Advanced Lithography.

[5]  Mingying Ma,et al.  Coma measurement of projection optics in lithographic tools based on relative image displacements at multiple illumination settings. , 2007, Optics express.

[6]  V.L. Rideout,et al.  One-device cells for dynamic random-access memories: A tutorial , 1979, IEEE Transactions on Electron Devices.

[7]  Chris A. Mack.  Thirty years of lithography simulation , 2004, SPIE Advanced Lithography.

[8]  Mingying Ma,et al.  Aberration measurement of projection optics in lithographic tools based on two-beam interference theory. , 2006, Applied optics.

[9]  H. Nomura,et al.  Techniques for measuring aberrations in lenses used in photolithography with printed patterns. , 1999, Applied optics.

[10]  Chris A. Mack,et al.  Lithography simulation in semiconductor manufacturing , 2005, SPIE/COS Photonics Asia.

[11]  Gerhard Kunkel,et al.  Aberration measurement using in-situ two-beam interferometry , 2001, SPIE Advanced Lithography.

[12]  Katsuyoshi Kobayashi,et al.  Impact of lens aberration on pattern symmetry of DRAM cells , 2000, Advanced Lithography.