Advanced resist process enabling implementation of CD controllability for 32 nm and beyond

Exposure wavelength has been changing dramatically as semiconductor design rules shrink, and for 32nm-node fine processes and beyond, it is predicted that the drop in optical contrast when using 193nm immersion lithography exposure technology will make it difficult to ensure good resolution performance in fine and dense resist patterns. To address this problem, studies have begun on extreme ultraviolet (EUV) lithography technology and double patterning technology that uses 193nm immersion lithography as alternative technologies, but many problems have been reported at the present stage of development. Against the above background, we investigated various process flows with the aim of reducing production processes and cost in double patterning technology that uses 193nm immersion lithography. We consequently developed an advanced process technique for use after 1st resist pattern formation and established a litho-litho-etch (LLE) process. The application of this technology decreases the number of total processes used in ordinary double patterning technology. In this paper, we focus on double patterning technology in 193nm immersion lithography and report on the performance of our original advanced process technique and on our evaluation of double patterning technology.