Lithography of choice for the 45-nm node: new medium, new wavelength, or new beam?

Uesawa, Fumikatsu; Katsumata, Mikio; Ogawa, K.; Takeuchi, Koichi; Omori, Shinji; Yoshizawa, Masaki; Kawahira, Hiroichi

doi:10.1117/12.535104

Cited by 6 publications

(5 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Features as small as 45 nm can be fabricated when combined with water-immersion lithography [2,7]. Even smaller dimensions can be contemplated by combining 193 nm illumination with a higher index matching fluid [4].…”

Section: The Ultimate Feature Sizes Achievable By Ilmentioning

confidence: 99%

See 1 more Smart Citation

Interference lithography: a powerful tool for fabricating periodic structures

Lipson²

2010

Laser & Photonics Reviews

268

174

View full text Add to dashboard Cite

In this review the basic principles of interference lithography (IL) are described. IL is emerging as one of the most powerful yet relatively inexpensive methodologies for creating large-area patterns with micron-to sub-micron periodicities.-dimensional periodic structures ( ) can be obtained by interfering ( ) non-coplanar beams in a photoresist. The symmetry and shape of the "unit cell" can be conveniently controlled by varying the intensities, geometries, polarizations, and phases of the beams involved. IL done with shorter wavelength lasers and/or liquid immersion lithography can create features with sub-50 nm dimensions. Such periodic structures are beginning to find wide use in photonic crystal science, optical telecommunications, data storage, and the integrated circuit industry. Newer innovations such as diffraction element assisted lithography or DEAL and phase-controlled IL for making twodimensional structures are also discussed.SEM images of two-dimensional patterns created by three-beam non-coplanar interference lithography. The upper left hand image corresponds to the case when the phases of the three beams used to make the exposure are equal. The remaining images correspond to situations where one laser beam has been given a different phase relative to the other two beams when making the exposure.

show abstract

Section: The Ultimate Feature Sizes Achievable By Ilmentioning

confidence: 99%

“…Photolithography is widely used in microelectro-mechanical systems (MEMS) to create integrated circuits (IC). The combination of short wavelength light sources [2,3] and innovations such as immersion lithography [4][5][6][7][8] and phase shift masks [3,9] have pushed the feature size well into the nanometer scale.…”

Section: Introductionmentioning

confidence: 99%

Interference lithography: a powerful tool for fabricating periodic structures

Lipson²

2010

Laser & Photonics Reviews

268

174

View full text Add to dashboard Cite

show abstract

“…Note that both of them correspond to the 45-nm node. The process margin requirements applied for this calculation were taken from the report by Uesawa, et, al 7 . The illumination condition was set to be NA/σ = 1.07/0.95 and 1.20/0.95.…”

Section: Error Budget For the 45-nm Nodementioning

confidence: 99%

A novel strategy of lithography-error-budget optimization for the 65-nm node: mask specifications for hyper-NA imaging

et al. 2005

Self Cite

View full text Add to dashboard Cite

This paper presents the first results on mask critical-dimension (CD) specifications for the hyper-numerical aperture (hyper-NA) lithography. The mask CD specifications have been derived from experimental results applying the immersion lithography with NA being 0.85. The experiment has been performed for a hole pattern corresponding to the 65-nm node with NA = 0.75 or 0.85. From this experiment, it was found that the higher-NA condition (NA = 0.85) makes the mask CD tolerance being more than doubled as compared to that under the lower-NA condition of NA = 0.75 while retaining the depth-of-focus (DOF) margin. This relaxation in the CD tolerance is attributable to the enlargement of DOF in the immersion lithography where the DOF becomes more than n times larger than that with the dry lithography under the same resolution limit (n: refractive index of immersion fluid). Analyses of the mask CD tolerance have been performed by applying a newly-developed method, that enables a quantitative analysis of mask CD error and DOF margin. In addition, the mask CD error margin for the 45-nm node have also been estimated by performing a lithography simulation under conditions with NA = 1.07 and 1.20. From this simulation, it was predicted that for the case when NA = 1.07, the mask CD error margin requires specifications on mask that are almost unachievable if one concerns the status of current mask manufacture processes together with the forecast on the processes given in the ITRS 2004 roadmap. On the other hand, the simulation predicted that the higher-NA condition (NA = 1.20) with the immersion imaging realizes a relaxation in the mask CD tolerance, leading to realistic specifications on mask. Therefore, this strategy realizes a breakthrough to avoid the "mask crises".

show abstract

“…The process margin requirements applied for this calculation were taken from the report by Uesawa, et, al. 8 The illumination condition was set to be NA/σ = 1.07/0.95 and 1.20/0.95. The conventional illumination and the 6% att-PSM were applied to both of the cases.…”

Section: Mask CD Tolelance In Immersion Lithographymentioning

confidence: 99%

Mask specifications for 45-nm node: the impact of immersion lithography and polarized light imaging

2006

Self Cite

View full text Add to dashboard Cite

This paper presents the impact of hyper-NA (NA > 1) lithography on the specification of mask critical-dimension (CD) uniformity. In order to realize the hyper-NA lithography, it is needed to adopt new technologies such as a liquid-immersion setup and polarized light illuminator. In the immersion lithography, it has been shown that the mask CD tolerance can be relaxed if NA is increased. This relaxation originates from the increase of the exposure-latitude (EL) in defocus conditions. As has also been reported, polarized light imaging enhances the EL of line-and-space patterns. This indicates that the application of polarized light imaging may enable us to relax the mask CD tolerance. In this paper, the mask CD relaxation will be discussed based on lithography simulations. In addition, the influences of mask birefringence and state of polarization in illuminator on the wafer CD will be discussed. Quartz substrate used as a mask blank can act as a rotation retarder, because of the presence of intrinsic stress induced in manufacturing processes. Therefore, the state of polarization of mask-transmitted light is disturbed. As a result, wafer CD is affected both by the mask birefringence and state of polarization in illuminator; hence, specification of mask CD uniformity (CDU) is also influenced. In this paper, the specification of mask CDU will be discussed by taking the effect of the impact of state of polarization in illuminator and mask birefringence into account. These results accelerate the practical use of hyper-NA lithography in 45-nm node.

show abstract

Lithography of choice for the 45-nm node: new medium, new wavelength, or new beam?

Cited by 6 publications

References 4 publications

Interference lithography: a powerful tool for fabricating periodic structures

Interference lithography: a powerful tool for fabricating periodic structures

A novel strategy of lithography-error-budget optimization for the 65-nm node: mask specifications for hyper-NA imaging

Mask specifications for 45-nm node: the impact of immersion lithography and polarized light imaging

Contact Info

Product

Resources

About