Flare in EUV mirror optics has been reported to be very high and long range effect due to its character which is inversely proportional to the 4 th order of wavelength. The high level of flare will generate CD (Critical Dimension) variation problem in the area where the gradient of aerial pattern density is large while the long range influencing character would confront an issue of computational challenge either for OPC (Optical Proximity Correction) modeling or for any other practical ways to accommodate such a long range effect. There also exists another substantial challenge of measuring and characterizing such a long range flare accurately enough so that the characterized flare can successfully be used for the compensation in the standard OPC flow.In this paper, the ZRAM (Zonal Ring Approximation Method), a practical and robust method for EUV flare characterization is introduced and assessed by simulation and also by experiment. Several fractal type of functional model PSFs (Point Spread Functions) that can be considered to be spanning the range of potential PSF are assumed and compared with known calculated value of the PSF which is derived from the surface roughness of mirrors comprising the ADT projection optics. Lithographic behaviors in EUV flare can possibly approximated by using single or double fractal model PSF. Experimental result shows that the ZRAM could be successfully used as a tool for the flare characterization and the system flare turned out to be having substantially large mid and long influence range.Flare compensation of using flare map could be adopted well in the OPC flow because at least down to 1um pixel resolution seems to be enabled by means of fast convolution method based on the re-sampling algorithm. Flare map of DRAM device layer which is thought to undergo the largest flare impact could be generated within a doable execution time.

No abstract

No abstract

No abstract

Polymer structure effect on dissolution characteristics and acid diffusion in chemically amplified deep ultraviolet resists J.