[1] [1] Oyama K, Yamauchi S, Hara A, et al. Sustainability and applicability of spacer-related patterning towards 7nm node［J］. SPIE, 2015, 9425: 942514.

[2] [2] Gao W, Ciofi I, Saad Y, et al. Rigorous assessment of patterning solution of metal layer in 7nm technology node［J］. Journal Micro/Nanolithography Mems & Moems, 2016, 15(1): 013505.

[3] [3] Graaf R D, Weichselbaum S, Droste R, et al. NXT: 1980Di immersion scanner for 7nm and 5nm production nodes［J］. SPIE, 2016, 9780: 978011.

[4] [4] Verstappen L, Mos E, Wardenier P, et al. Holistic overlay control for multi-patterning process layers at the 10 nm and 7 nm nodes［J］. SPIE, 2016, 9778: 97781Y.

[5] [5] Gorhad K, Sharoni O, Dmitriev V, et al. Co-optimization of RegC and TWINSCANTM corrections to improve the intra-field on-product overlay performance［J］. SPIE, 2016, 9778: 97783D.

[6] [6] Mulkens J, Hinnen P C, Kubis M, et al. Holistic optimization architecture enabling sub-14-nm projection lithography［J］. Journal Micro/Nanolithography Mems & Moems, 2014, 13(1): 011006.

[7] [7] Den Boef A J, Hoogerland M, Gajdeczko B. Alignment system and method: US7564534B2［P］. 2009-7-21.

[8] [8] Nagayama T, Nakajima S, Sugaya A, et al. New method to reduce alignment error caused by optical system［J］. SPIE, 2003, 5038: 849-860.

[9] [9] Castenmiller T, Van de Mast F, de Kort T, et al. Towards ultimate optical lithography with NXT: 1950i dual stage immersion platform［J］. SPIE, 2010, 7640(3): 76401N.

[10] [10] Charley A L, Leray P, Pypen W, et al. High speed optical metrology solution for after etch process monitoring and control［J］. SPIE, 2014, 9050(1): 90501H.

[11] [11] Miyasaka M, Saito H, Tamura T, et al. The application of SMASH alignment system for 65-55-nm logic devices［J］. SPIE, 2007, 6518: 65180H.

[12] [12] Si Xinchun, Tong Junmin, Tang Yan, et al. Lithography alignment technology based on two-dimensional Ronchi grating［J］. Chinese J Lasers, 2015, 42(9): 0910001.

[13] [13] Si Xinchun, Tang Yan, Hu Song, et al. High-precision alignment technique with large measurement range based on composite gratings［J］. Acta Optica Sinica, 2016, 36(1): 0105003.

[14] [14] Lei M, Yao B L, Rupp R A. Structuring by multi-beam interference using symmetric pyramids［J］. Optics Express, 2006, 14(12): 5803-5811.

[15] [15] Barrell H, Sears J E. The refraction and dispersion of air for the visible spectrum［M］. Philosophical Transactions of the Royal Society of London, 1939, 238(786): 1-64.