Approaching the numerical aperture of water immersion lithography at 193-nm

Smith, Bruce W.; Bourov, Anatoly; Fan, Yongfa; Zavyalova, Lena; Lafferty, Neal; Cropanese, Frank

doi:10.1117/12.537262

Cited by 20 publications

(4 citation statements)

References 12 publications

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“…These additives included both organic and inorganic species. Of these additivies, ionic species seemed to result in the most significant increase in the index 4,5 . A study of the optical properties of a variety of metal salts with halide and polyatomic anions, acids, sodium salts, and microelectronics-friendly quaternary ammonium salts has been completed.…”

Section: Introductionmentioning

confidence: 93%

New high-index fluids for immersion lithography

et al. 2006

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Immersion lithography at 193nm has rapidly evolved from a novel technology to the top contender for the 45nm device node. The likelihood of immersion implementation in semiconductor manufacturing has raised interest in expanding its capabilities. Extending resolution requires immersion fluids with higher refractive indices than those currently available. We have therefore sought substances which, when added to water, increase the refractive index at 193nm without increasing the absorbance and viscosity beyond acceptable limits. This work explores the relationship between index of refraction and absorbance, with specific focus on the identification of fluids that have a high index and low absorbance. The majority of the fluids studied either have prohibitively high absorbance values or material properties that would be incompatible with current fluid handling systems. However, a class of methylsulfonate salts was identified with optical and material properties approaching the target values. Fluid testing and imaging is included to confirm the resolution enhancing capability of these new high index fluids.

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Section: Introductionmentioning

confidence: 93%

New high-index fluids for immersion lithography

et al. 2006

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“…A Talbot immersion interference lithography setup has been employed to achieve these results. The system description has been presented earlier [2]. The setup is shown in Figure 5.…”

Section: Materials Limitsmentioning

confidence: 99%

25 nm immersion lithography at 193 nm wavelength

Smith

Fan

Slocum

et al. 2005

Optical Microlithography XVIII

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The physical limitations of lithographic imaging are ultimately imposed by the refractive indices of the materials involved. At oblique collection angles, the numerical aperture of an optical system is determined by nsin(θ) , where n is the lowest material refractive index (in the absence of any refractive power through curvature). For 193nm water immersion lithography, the fluid is the limiting material, with a refractive index of near 1.44, followed by the lens material (if planar) with a refractive index near 1.56, and the photoresist, with a refractive index near 1.75. A critical goal for immersion imaging improvement is to first increase the refractive indices of the weakest link, namely the fluid or the lens material. This paper will present an approach to immersion lithography that will allow for the exploration into the extreme limits of immersion lithography by eliminating the fluid altogether. By using a solid immersion lithography (SIL) approach, we have developed a method to contact the last element of an imaging system directly to the photoresist. Furthermore, by fabricating this last element as an aluminum oxide (sapphire) prism, we can increase its refractive index to a value near 1.92. The photoresist becomes the material with the lowest refractive index and imaging becomes possible down to 28nm for a resist index of 1.75 (and 25nm for a photoresist with a refractive index of 1.93). Imaging is based on two-beam Talbot interference of a phase grating mask, illuminated with highly polarized 193nm ArF radiation. Additionally, a roadmap is presented to show the possible extension of 193nm lithography to the year 2020.

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“…A piezoelectric actuator is a device that converts electrical energy into mechanical motion through the anti-piezoelectric effect. It has been widely applied in micro/nano operations [1,2] and other high-precision instruments, such as optical alignment [3,4], microsurgical instruments [5,6], and lithography [7,8]. Consequently, it has attracted the attention of many researchers in related fields.…”

Section: Introductionmentioning

confidence: 99%

A stick-slip piezoelectric actuator with suppressed backward motion achieved using an active locking mechanism (ALM)

Dong

Zhang

et al. 2021

Smart Mater. Struct.

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Backward motion commonly exists in the stick-slip linear piezoelectric actuator, resulting in deterioration of the output performance and limiting their applications. To solve the problem, a stick-slip linear piezoelectric actuator with suppressed backward motion, achieved using an active-locking mechanism (ALM) with two mechanisms, is proposed in this paper. One mechanism involves stick-slip driving, while the other actively suppresses backward motion by clamping the slider during the backward driving process through efficient control. A prototype actuator was designed and manufactured to verify the feasibility of this method, and an experimental system was established to obtain the detailed parameters. Also, to verify the feasibility and effectiveness of the suppression effect on backward motion of the proposed actuator, the output performance of the traditional stick-slip actuator and the actuator with the ALM were compared. Based on the results, we demonstrate that the maximum output speed and maximum output force of the prototype are 2.26 mm s−1 and 1.6 N under a voltage of 100 V, respectively.

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Approaching the numerical aperture of water immersion lithography at 193-nm

Cited by 20 publications

References 12 publications

New high-index fluids for immersion lithography

New high-index fluids for immersion lithography

25 nm immersion lithography at 193 nm wavelength

A stick-slip piezoelectric actuator with suppressed backward motion achieved using an active locking mechanism (ALM)

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