Study of nanoimprint lithography (NIL) for HVM of memory devices

Kono, Takuya; Hatano, Masayuki; Tokue, Hiroshi; Kobayashi, Kei; Suzuki, Masato; Fukuhara, Kazuya; Asano, Masafumi; Nakasugi, Tetsuro; Choi, Eun Hyuk; Jung, Wanyeong

doi:10.1117/12.2257951

Cited by 6 publications

(9 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…UV nanoimprint lithography (UV-NIL) has been attracting intense interest because of its potential for fine patterning at the single-digit nanometer scale and atomic-scale low line-edge roughness, in addition to the high throughput and low cost of imprint steppers in the nanofabrication process. − In the semiconductor industry, nanofabrication technology has been progressing according to Moore’s law, predicting a yearly increase in the density of devices, but is considered to face its limitation. The UV-NIL process with fused silica molds (quartz molds) is expected to be a candidate to break the limitation.…”

Section: Introductionmentioning

confidence: 99%

Selection of Diacrylate Monomers for Sub-15 nm Ultraviolet Nanoimprinting by Resonance Shear Measurement

et al. 2018

View full text Add to dashboard Cite

In UV nanoimprinting, the selection of monomers suitable for sub-15 nm patterning is difficult because the filling behavior of resin at this scale still remains scientifically unclear. We demonstrate sub-15 nm patterning by UV nanoimprinting using silica molds with 20, 15, and 7 nm diameter holes; however, the 7 nm diameter pillar patterns were not fabricated using hydroxy-containing monomers. The filling behavior into silica holes of around 10 nm depended on the chemical structure of the monomers. Resonance shear measurements revealed the following: (1) The viscosities of hydroxy-containing monomers confined between chlorodimethyl(3,3,3-trifluoropropyl)silane (FAS3-Cl)-modified surfaces began to increase at distances shorter than those of the monomers between unmodified surfaces. (2) The monomers confined between tridecafluoro-1,1,2,2-tetrahydrooctyltrimethoxysilane-modified surfaces were squeezed out when the surface-surface distance decreased at less than 7 nm. The measured viscosities between the FAS3-Cl-modified silica surfaces were correlated with the insufficient filling behavior into the silica holes of around 10 nm in UV nanoimprinting. Contact angle measurements provided an additional insight that a higher wettability of the monomers onto the antisticking chemisorbed monolayers resulted in imprinted patterns with higher aspect ratios. Considering the increase in the monomer viscosity in the nanospace and the wettability of monomers onto chemisorbed monolayers, we concluded that the monomer showing low viscosity under confinement and high wettability onto the mold surface was suitable for single-digit nanometer UV nanoimprinting.

show abstract

Section: Introductionmentioning

confidence: 99%

Selection of Diacrylate Monomers for Sub-15 nm Ultraviolet Nanoimprinting by Resonance Shear Measurement

et al. 2018

View full text Add to dashboard Cite

show abstract

“…It is very close to the target, but it requires further improvement to meet the future demand. However, the CDU and LER are found to be less than 2 nm [57].…”

Section: Status and Challengesmentioning

confidence: 79%

“…To reduce the particle defects, which are located on the wafer and mask, some approaches have been taken including air curtain system and polishing [55,56]. Recently, it has been revealed that defectivity level has been lessened to below 1 pcs per cm 2 at a throughput of 15 wafers per hour [57]. Another key issue of NIL that should be realized is nano-defect management (NDM) technology that includes defect inspection of templates and imprinted wafer, the resist material innovation and the defect mitigation.…”

Section: Status and Challengesmentioning

confidence: 99%

Promising Lithography Techniques for Next-Generation Logic Devices

2018

View full text Add to dashboard Cite

Continuous rapid shrinking of feature size made the authorities to seek alternative patterning methods as the conventional photolithography comes with its intrinsic resolution limit. In this regard, some promising techniques have been proposed as next-generation lithography (NGL) that has the potentials to achieve both high-volume production and very high resolution. This article reviews the promising NGL techniques and introduces the challenges and a perspective on future directions of the NGL techniques. Extreme ultraviolet lithography (EUVL) is considered as the main candidate for sub-10-nm manufacturing, and it could potentially meet the current requirements of the industry. Remarkable progress in EUVL has been made and the tools will be available for commercial operation soon. Maskless lithography techniques are used for patterning in R&D, mask/mold fabrication and low-volume chip design. Directed self-assembly has already been realized in laboratory and further effort will be needed to make it as NGL solution. Nanoimprint lithography has emerged attractively due to its simple process steps, high throughput, high resolution and low cost and become one of the commercial platforms for nanofabrication. However, a number of challenging issues are waiting ahead, and further technological progresses are required to make the techniques significant and reliable to meet the current demand. Finally, a comparative study is presented among these techniques.

show abstract

“…Nanoimprint lithography (NIL) using ultraviolet (UV) radiation is a potential candidate process for semiconductor manufacturing. [1][2][3][4][5][6][7][8] Typically, drop-and-cure NIL technology includes four process steps, i.e., resist dropping, resist spreading, UV irradiation, and separation. [4][5][6][7] One of the critical issues of NIL is throughput.…”

Section: Introductionmentioning

confidence: 99%

Meniscus behavior under helium exposure for rapid resist spreading during nanoimprint lithography

Kashiwagi

Sato

Hatano

et al. 2018

Jpn. J. Appl. Phys.

Self Cite

View full text Add to dashboard Cite

Nanoimprint lithography under helium exposure plays an important role in realizing rapid resist spreading. It is expected that the reduction in the surface tension of the resist due to the diffusion of helium would have an impact on the spreading behavior of the resist. By assuming van der Waals potential, the surface tension of the resist under helium exposure is estimated to be reduced by 70%. In our experiment, we obtain an 83% reduction in the surface tension of a resist under helium exposure by evaluating the meniscus shape at the corner of a rectangular imprinted area after UV curing. Furthermore, the C/O composition ratio of the resist after UV curing is found to change due to the exposure. Our study confirms that helium strongly affects the surface tension of the resist. The result also suggests the possibility of the supercritical fluidic behavior of helium in the resist. The resist spreading velocity can be increased by 2.5 times by helium exposure.

show abstract

Study of nanoimprint lithography (NIL) for HVM of memory devices

Cited by 6 publications

References 5 publications

Selection of Diacrylate Monomers for Sub-15 nm Ultraviolet Nanoimprinting by Resonance Shear Measurement

Selection of Diacrylate Monomers for Sub-15 nm Ultraviolet Nanoimprinting by Resonance Shear Measurement

Promising Lithography Techniques for Next-Generation Logic Devices

Meniscus behavior under helium exposure for rapid resist spreading during nanoimprint lithography

Contact Info

Product

Resources

About