ASML's NXE platform is a multi-generation TWINSCAN™ platform using an exposure wavelength of 13.5nm, featuring a plasma source, all-reflective optics, and dual stages operating in vacuum. The NXE:3100 is the first product of this NXE platform. With a 0.25 NA projection optics, a planned throughput of 60 wafers/hr and dedicated chuck overlay of 4 nm, the NXE:3100 is targeted for extreme ultraviolet lithography (EUVL) implementation at 27nm halfpitch (hp) and below. The next generation NXE tools utilize a 0.33NA lens and include off-axis illumination for high volume manufacturing at a resolution down to 16nm hp and a targeted throughput of >100 wafers/hr. We share details of the performance of the 0.25NA lithography products in terms of imaging, overlay, throughput, and defectivity. We will show that we have met the required imaging performance associated with the 27nm hp node. We will also include a summary of the EUV source development, which is a key enabler for cost-effective introduction of EUVL into highvolume manufacturing. Finally, we will highlight some of the technical changes we introduced to enable the transition from 27 to 22nm lithographic performance while introducing our 0.33NA Step & Scan system, the NXE:3300B.

Advanced optical systems for low k 1 lithography require accurate characterization of various imaging parameters to insure that OPC strategies can be maintained. Among these parameters lens aberrations and illumination profiles are the most important optical column characteristics. The phase measurement interferometer hardware (ILIAS™ : Integrated Lens Interferometer At Scanner) integrated into high-NA ArF lithographic projection tools opens novel pathways to measure and control tool critical performance parameters. In this presentation we address new extensions of this in-line tool that will allow the measurement of optical parameters of the full optical column. The primary functionality of the ILIAS™ system is to measure and analyse wavefront aberrations across the full image field with high accuracy and speed. In this paper performance data of the in-line wavefront sensor over multiple high-NA ArF lithographic systems is presented. In addition to the acquisition of wavefront aberrations in terms of Zernike polynomials, detailed measurements of high resolution wavefronts are now possible. Examples of such wavefronts and PSD analysis thereof are presented. Besides the projection lens properties, the detailed shape of the pupil distribution and transmission (apodisation) becomes critical for system optimization. The integrated ILIAS™ hardware can also be used to measure these parameters.

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We present a comprehensive modeling study of polarization effects for the whole optical chain including exposure tool and mask, with strong emphasis on the impact of the Jones Matrix of the projection lens. First we start with the basic of polarization and then the polarization effect of each components of the optical chain will be discussed. Components investigated are source polarization, rigorous EMF effect, mask blank birefringence, pellicle effect and projection lens. We also focus on comparing the relative merits of different types of representation of Jones matrix of the projection lens and outlined ways to decompose the Jones Matrix. Methodologies such as Pauli matrix, PQM, Jones-Zernike expansion and IPS-Zernike expansion are among the ones investigated. The polarization impact on lithography and OPC on realistic 45nm and 32nm node process levels is discussed. Issues in OPC modeling with Jones Matrix is highlighted. Concerns regarding the standardization of the implementation of Jones Matrix in the lithography community are considered and a standard has been proposed and received wide acceptance. Last we discuss the challenge of using polarization and some novel ideas to deal with polarization in hyper NA era. Throughout the paper the resist component is not included so as to isolate the effect of resist from that of the other components. INTRODUCTIONThe advent of optical immersion lithography has dissolved the NA=1 barrier and is carving novel pathways for advanced semiconductor manufacturing. Nowadays hyper-NA (NA >1) immersion lithography is considered to be a strong contender for device manufacturing at the 45nm and 32nm nodes. The use of water immersion enables a further increase in resolution and is strongly competing with the option of an early wavelength transition to EUV.

The introduction of polarized light in high NA lithography requires additional characterization metrics for illumination systems. It has been shown that the percentage of the total light intensity that is polarized in the desired direction is a metric that can be closely related to wafer CD. On ASML systems, this quantity is called IPS (Intensity in Preferred State). Illuminators are characterized in terms of the minimum IPS found somewhere across the illuminated area and the IPS Range.In case the mask has a finite birefringence, there is an additional impact on the effective IPS. After passing through the mask blank, the IPS of the light will have changed and hence, there will be a response for wafer CD. Mask birefringence in conjunction with IPS introduces an additional contribution for the CD budget. This work will focus on the impact of mask birefringence on wafer CD for different scenarios of polarized illumination. We will show that the angle of the fast axis of birefringence can have a much greater impact on CD than the maximum birefringence magnitude itself. Based on these results we will derive a requirement for mask birefringence which has it's foundation on CD. We will present measurements of the birefringence distributions of mask blanks, patterned masks, and masks with pellicles to investigate the contribution of the mask process flow starting from substrate, material deposition, processing, and final pellicle application. In addition to the material properties of the pellicle, the mounting of the pellicle to the substrate may induce additional stress birefringence.

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A second phase in the immersion era is starting with the introduction of ultra high NA (NA >1) systems. These systems are targeting for 45 nm node device production and beyond. ASML TWINSCAN XT:1700i features a maximum NA of 1.2 and a 26x33 mm 2 scanner field size. The projection lens is an in-line catadioptric lens design and the AERIAL XP illumination system enables conventional an off-axis illumination pupil shapes in either polarized or un-polarized modes at maximum light efficiency. In this paper a description and a performance overview of the TWINSCAN XT:1700i is given. We will present and discuss lithographic performance results, with special attention at low-k1 imaging using high NA and polarized illumination. Overlay, focus and productivity performance will also be presented.