High reflectance of reflective-type attenuated-phase-shifting masks for extreme ultraviolet lithography with high inspection contrast in deep ultraviolet regimes

Chen, H. L.; Cheng, Hsu Chun; Ko, Tsung-Shine; Ko, Fu‐Hsiang; Chu, T. C.

doi:10.1116/1.1813450

Cited by 9 publications

(3 citation statements)

References 8 publications

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“…10 Soon after that Obert Wood et al from Lucent reported the first experimental realization of attPSM for EUV including extensive simulation studies. 11 Since then, many different forms of attPSM for EUV including etched multilayer configurations [12][13][14] and various absorber stack configurations [15][16][17] were proposed and investigated.…”

Section: Introductionmentioning

confidence: 99%

Attenuated phase shift mask for extreme ultraviolet: can they mitigate three-dimensional mask effects?

2018

J. Micro/Nanolith. MEMS MOEMS

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The understanding, characterization, and mitigation of three-dimensional (3-D) mask effects including telecentricity errors, contrast fading, and best focus shifts become increasingly important for the performance optimization of future extreme ultraviolet (EUV) projection systems and mask designs. We explore the potential of attenuated phase shift mask (attPSM) to mitigate 3-D mask effects and exploit them for future EUV imaging. The scattering of light at the absorber edges results in significant phase deformations, which impact the effective phase and the lithographic performance of attPSM for EUV. Rigorous mask and imaging simulations in combination with multiobjective optimization techniques are employed to identify the most appropriate material properties, mask, and source geometries. The resulting imaging performance is compared to the achievable performance of binary EUV masks.

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Section: Introductionmentioning

confidence: 99%

Attenuated phase shift mask for extreme ultraviolet: can they mitigate three-dimensional mask effects?

2018

J. Micro/Nanolith. MEMS MOEMS

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“…Recently, various materials such as TaN, TaBN, TaSiN, Al 2 O 3 , Cr, and ITO have been studied as high-absorbance materials [7][8][9][10][11][12][13]. Further reduction in the thickness of the absorber layer, to prevent the geometric shadow effect in the exposure step, is challenging [14,15]. Hence, it is essential to develop new mask materials with low thickness and high optical contrast for use in circuit printing and defect inspection.…”

Section: Introductionmentioning

confidence: 99%

Binary mask designs with single- and double-layer absorber stacks for extreme ultraviolet lithography and actinic inspection

et al. 2013

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In this study, we propose binary mask (BIM) designs with single- and double-layer absorber stacks with high optical contrast at a wavelength of 13.5 nm for use in extreme ultraviolet lithography (EUVL) and actinic defect inspection. The optimum thickness of the absorber stack was estimated using a method based on the transfer matrix. In the double-layer designs, [Ag/SnTe] has a minimum thickness of ∼32 nm with almost 100% optical contrast compared to the TaN layer. In addition, a SnTe absorber layer was deposited using radio frequency magnetron sputtering. The optical constant of the SnTe layer at 13.5 nm wavelength was determined using the density of the layer, which was obtained from x-ray reflectivity measurements. The reflectance of the SnTe single-layer absorber stack was measured in the EUV region and compared with the simulated reflectance by using the calculated optical constants. The results show that the new BIM designs for EUVL and actinic inspection can be helpful in reducing the geometric shadow effect compared to the TaN absorber layer with a thickness of ∼70 nm.

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“…However, it is reported that the lithography performance of an EUVL mask depends on the thickness of absorber materials because it is directly related to the imaging contrast, shadowing effect, focus shift effect, and thermal effect [2]. Therefore, the development of novel mask materials with high absorption at EUV is important for an actinic inspection of the mask and a high numerical aperture (NA) optical system [3].…”

Section: Introductionmentioning

confidence: 99%

Determination of Optical Constants of Thin Films in Extreme Ultraviolet Wavelength Region by an Indirect Optical Method

Kang¹,

Lim²,

Peranantham³

et al. 2013

Journal of the Optical Society of Korea

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In this study, we propose a simple and indirect method to determine the optical constants of Mo and ITO thin films in the extreme ultraviolet (EUV) wavelength region by using X-ray reflectometry (XRR) and Rutherford backscattering spectrometry (RBS). Mo and ITO films were deposited on silicon substrates by using an RF magnetron sputtering method. The density and the composition of the deposited films were evaluated from the XRR and RBS analysis, respectively and then the optical constants of the Mo and ITO films were determined by an indirect optical method. The results suggest that the indirect method by using the XRR and RBS analysis will be useful to search for suitable high absorbing EUVL mask material quickly.

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High reflectance of reflective-type attenuated-phase-shifting masks for extreme ultraviolet lithography with high inspection contrast in deep ultraviolet regimes

Cited by 9 publications

References 8 publications

Attenuated phase shift mask for extreme ultraviolet: can they mitigate three-dimensional mask effects?

Attenuated phase shift mask for extreme ultraviolet: can they mitigate three-dimensional mask effects?

Binary mask designs with single- and double-layer absorber stacks for extreme ultraviolet lithography and actinic inspection

Determination of Optical Constants of Thin Films in Extreme Ultraviolet Wavelength Region by an Indirect Optical Method

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