In this paper we discuss edge placement error (EPE) for multi-patterning application and compare the EPE budget with the one for EUV single expose application case. These two patterning methods are candidate for the manufacturing of 10-nm and 7-nm logic semiconductor devices. EUV will enable 2D random pattern layout, while in the multi-patterning case a more restricted 1D design layout is needed. For the 1D design approach we discuss the patterning control spacer pitch division resulting in complex multi-layer alignment and EPE optimization strategies. Solutions include overlay and CD metrology based on angle resolved scatterometry, scanner actuator control to enable high order overlay corrections and computational lithography optimization to minimize imaging induced pattern placement errors of devices and metrology targets. We use 10-nm node experimental data and extrapolate the error budgets towards the 7-nm technology node. The experimental data will be based on NXE:3300B and NXT:1960Bi/NXT:1970Ci exposure systems. The results are compared to the more straightforward alternative of using single expose patterning with EUV for all critical layers.

This paper discusses the current performance and the evolution of five generations TWINSCAN immersion scanning exposure tools. It is shown that production worthy overlay and focus performance can be achieved at high scan speeds. The more critical part for immersion tools is related to defects, but also here improvements resulted in production worthy defect levels. In order to keep the defect level stable special measures are needed in the application of wafers. Especially Edge Bead Removal (EBR) design and wafer bevel cleanliness are important.

As the semiconductor industry looks to the future to extend manufacturing beyond 100nm, ASML have developed a new implementation of an old optical method for lithography. Immersion lithography can support the aggressive industry roadmap and offers the ability to manufacture semiconductor devices at a low k1.In order to make immersion lithography a production worthy technology a number of challenges have to be overcome. This paper provides the results of our feasibility study on immersion lithography. We show through experimental and theoretical evaluation that we can overcome the critical concerns related to immersion lithography. We show results from liquid containment tests focussing on its effects on the scan speed of the system and the formation of microbubbles in the fluid. We present fluid-to-resist compatibility tests on resolution, using a custom-built interference setup. Ultimate resolution is tested using a home build 2 beam interference setup. ASML built a prototype full field scanning exposure system based on the dual stage TWINSCAN TM platform. It features a full field 0.75 NA refractive projection lens. We present experimental data on imaging and overlay.keywords: immersion lithography, high NA, TWINSCAN, bath, shower 1.INTRODUCTIONFor more than 25 years the semiconductor industry has predicted the end of optical lithography. Recent developments, however, show us that optical lithography is more alive than ever before. Immersion lithography has emerged as the potential technology for extending optical lithography. Immersion lithography makes use of fluids with refractive indexes that are greater than 1.0 (the refractive index of air) to enable the use of lenses that have Numerical Apertures (NAs) larger than 1.0. Immersion, in principle, is not a new technique. Its viability for microlithography, however, has become a practical consideration because of advances made in lens manufacturing technology, especially a-spherical surface figuring. For 193-nm lithography, water proves to be a suitable immersion fluid. The refractive index for water is 1.43, which makes lens NAs above 1.2 feasible. Immersion offers the potential to extend conventional optical lithography to the 45-nm node and even potentially to the 32-nm node. The main challenges for deployment of immersion are in the design of the exposure tool. Early work done by International Sematech shows that existing photo resists can be compatibility with immersion. However, further work is required in this area.In this paper we discuss the achievements of both exposure tool design and the interaction between existing photoresists and immersion fluids. Section 2 provides the results of our feasibility study on immersion lithography. Section 3 shows the results of our prototype TWINSCAN TM immersion scanner, and finally section 4 summarizes the conclusions of this paper.

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