EUVL Square Mask Patterning with TaN Absorber

Yan, Pei-yang; Ma, Anna; Huang, Yi‐Chiau; Stoehr, Brigitte C.; Valdivia, J. A.

doi:10.1117/12.468102

Cited by 4 publications

(2 citation statements)

References 2 publications

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“…Different buffer layer materials eg. thin films of sputtered Cr or SiO 2 and different buffer wet and dry etch processes have been reported in literature 2,3 . We investigated the dry etch behaviour of a 60nm sputtered thin SiO 2 film with a TaN absorber as masking layer.…”

Section: Introductionmentioning

confidence: 99%

SiO 2 buffer-etch processes with a TaN absorber for EUV mask fabrication

et al. 2004

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Extreme Ultraviolet Lithography (EUVL) is the favourite next generation lithography candidate for IC device manufacturing with feature sizes beyond 32nm. The SiO 2 buffer dry etching is a crucial step in the manufacture of the EUV mask due to stringent CD-and reflectance requirements. In contrast to conventional chromium absorber layers new absorber materials e.g. TaN require an adjustment of the SiO 2 buffer etch chemistry and process parameters to avoid a strong influence on the initial absorber profile and thickness. We have developed a SiO 2 buffer dry etch process that uses the structured TaN absorber as masking layer. A laser reflectometer was used during the SiO 2 dry etch process for process control and endpoint detection. Different dry etch processes with SF 6 /He, CF 4 and CHF 3 /O 2 etch chemistry have been evaluated and compared with regard to TaN-and SiO 2 -etch rate, TaN-and SiO 2 etch profile and Si capping layer selectivity. We focused our work on minimum feature sizes and simultaneous etching of different line (e.g. dense-and isolated lines) and hole patterns. Line and contact hole structures with feature sizes down to 100nm have been realized and characterized in a SEM LEO 1560. The whole mask patterning process was executed on an advanced tool set comprising of a Leica SB 350 variable shaped e-beam writer, a blank coater Steag HamaTech ASR5000, a developer Steag HamaTech ASP5000 and a two chamber UNAXIS mask etcher III.

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Section: Introductionmentioning

confidence: 99%

SiO 2 buffer-etch processes with a TaN absorber for EUV mask fabrication

et al. 2004

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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].…”

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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Extreme ultraviolet mask fabrication with high inspection contrast TaSiNx absorber stack

Wasson

Weisbrod

Mangat

et al. 2003

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

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Extreme ultraviolet lithography ͑EUVL͒ is a leading candidate for next generation lithography with the potential for extendibility beyond the 45 nm node. The three-layer absorber stack for EUVL reticles consists of an absorber, repair buffer and etch stop layers, while a two-layer absorber stack eliminates the etch stop layer. Improving inspection contrast is critically important to finding defects. In previous work, using TaSiN as the EUV absorber, the inspection contrast was less than 10%, which did not allow for effective defect detection to occur. However, other TaSiN properties such as thin film stress control and critical dimension etch bias were clearly superior to the Cr absorber. An improved process using a Ta-based absorber stack that maintains the beneficial characteristics of the film, on SEMI Standard P1-92 6025 format substrates, is discussed.

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EUVL Square Mask Patterning with TaN Absorber

Cited by 4 publications

References 2 publications

SiO 2 buffer-etch processes with a TaN absorber for EUV mask fabrication

SiO 2 buffer-etch processes with a TaN absorber for EUV mask fabrication

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

Extreme ultraviolet mask fabrication with high inspection contrast TaSiNx absorber stack

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