Fabrication of masks for EUVL requires the formation and patterning of both repair buffer and EUV absorber layers on top of a molybdenumlsilicon multi-layer substrate. Films used for buffer and absorber should have low stress, good uniformity and good etch selectivity to underlying layers. Low stress chromium and tantalum nitride absorber film deposition processes have been developed and characterized on fused silica substrates (6x6x114 inch) at the MCoC. Sputtered silicon oxide was used as the buffer layer for work reported in this paper. This paper describes the results of EUVL mask processing at the MCoC, including deposition and etch capabilities of these films. Properties ofthe low stress chromium and tantalum nitride materials will be discussed, including stoichiometry, stress, uniformity and density. The chromium and tantalum nitride films have been integrated into a mask patterning process with a silicon oxide buffer layer. Etch bias and etch profiles from the two absorber films along with etch selectivities to the underlying silicon oxide layer will be presented. Image size results for both types of absorber layers will be presented, including the improvement in etch bias using the low stress chromium Complete EUVL masks with 1 60 nm feature sizes have been fabricated with these processes and micrographs of nested lines and elbows will be presented.

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Stress and image-placement distortions of 200 mm low-energy electron projection lithography masksElectron projection lithography mask format layer stress measurement and simulation of pattern transfer distortion J.Simulating the effects of pattern density gradients on electron-beam projection lithography pattern transfer distortions J.Membrane masks are needed for charged particle lithography and can include both stencil masks and masks with thin continuous membranes. Producing accurate image placement on membrane masks requires careful control of mask shape, pattern writing, and stress control of the mask materials. Pattern density and pattern density gradients also affect image placement ͑IP͒ control. This article discusses IP distortions on electron projection lithography masks caused by patterning the imaging layers with low and high density patterns and patterns with large gradients in the density. The process-induced distortion has been found to be largest with the largest vector distortion at the boundary when high pattern density gradients are present. The anisotropic stiffness of the unit cell also affects the process-induced distortion. Qualitatively, the results between continuous membrane and stencil masks show similar characters. The results provide distortion information that could be used to determine the maximum allowable membrane stress ͑for stencil masks͒ and scatterer layer stress ͑for continuous membrane masks͒ to meet necessary mask production targets.

Fabricating masks for extreme ultraviolet lithography is challenging. The high absorption of most materials at 13.4 nm and the small critical dimension (45 nm) at the target insertion node force many new features, including reflective mask design, new film choices, and stringent defect specifications. Fabrication of these masks requires the formation and patterning of both a repair buffer layer and an EUV absorber layer on top of a molybdenum/silicon multi-layer substrate.IBM and Photronics have been engaged in developing mask processing technology for x-ray, electron beam projection and extreme ultraviolet lithographies at the Next Generation Lithography Mask Center of Competency (NGL-MCoC) within IBM's mask facility at Essex Junction, Vermont. This paper describes recent results of mask fabrication on 6 x 6 x ¼ inch EUVL substrates (quartz with molybdenum silicon multi-layers) at the MCoC. Masks fabricated with high and low-stress chromium and externally deposited chromium absorber films are compared. In particular, etch characteristics, image size, image placement, line edge roughness, and defect levels are presented and compared. Understanding the influence of the absorber film characteristics on these parameters will enable us to optimize the effectiveness of a given absorber film or to select acceptable alternatives.

The Next Generation Lithography (NGL) Mask Center of Competency (MCoC) has been developing mask technology to support all of the major next generation lithographies for several years. Cross-cutting process development has been applied to generate progress in both the membrane and reflective mask formats. The mask technology has been developed to early capability stage for all of the mask formats. Proximity x-ray masks, although only for certain niche applications, are a very developed mask format. This information has been used to produce electron beam projection masks, in both continuous membrane and stencil formats, and extreme ultraviolet lithography masks. In this paper, we disucss the status of the lithography technology development and the obstacles that remain between the current early development capability and the availability for manufacturing.