Investigation of Photothermal Effects on the Liquid Field during the Exposure Process in Immersion Lithography

Abstract

Abstract Immersion lithography has been extending technology nodes to the sub-20nm regime of semiconductor manufacturing. Keeping the immersion liquid pure and uniform as well as avoiding residual droplets during high speed scanning motion are two challenges faced by the development of immersion lithography. During the exposure process of immersion lithography, the heat of the incident beam may cause the temperature rise of the immersion fluid which could result in the image placement on the silicon wafer. For this reason, the photothermal effects of the immersion fluid field during the exposure process are investigated in this paper to ensure the high-quality and stable-flowing of the immersion fluid, and consequently the accuracy of the pattern image transferred on the silicon wafer. Results obtained in this paper can provide solid guidance and definitely accelerate the development the immersion lithography in the sub-20nm regime.