A master-mold fabrication by electron beam lithography followed by nanoimprinting and self-aligned double patterning

Watanabe, Tsuyoshi; Suzuki, Kota; Iyama, Hiromasa; Kagatsume, Takeshi; Kishimoto, Shuji; Satō, Takashi; Kobayashi, Hideo

doi:10.7567/jjap.53.06jk05

Cited by 4 publications

(3 citation statements)

References 28 publications

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“…The fabrication of templates with sizes smaller than 20 nm for UV-NIL remains a challenge even with specific nanofabrication technologies. [22][23][24][25][26][27] Helium ion lithography is applied to the preparation of silica templates with a 4 nm linewidth. 28) The atomic layer deposition (ALD) of aluminum oxide is used to decrease the line width of concave patterns in HSQ templates.…”

Section: Introductionmentioning

confidence: 99%

Silica imprint templates with concave patterns from single-digit nanometers fabricated by electron beam lithography involving argon ion beam milling

Ito

Kikuchi

Watanabe³

et al. 2017

Jpn. J. Appl. Phys.

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To maintain the silica surface of imprint templates without a fluorine-containing passivation layer on sidewalls after dry etching, we investigated whether a physical dry etching process entailing exposure to Ar ion beam is useful for the fabrication of silica templates. An almost same etching rate of a positive-tone electron beam (EB) resist as silica in Ar ion beam milling allowed for the fabrication of bar-shaped patterns with micrometer lengths and widths for moiré alignment and of hole patterns with diameters of around 20 nm in silica templates. The EB resist layer of 40 nm thickness generated partially non-etched defects of 10-nm-diameter holes in silica templates because the Ar ion beam was completely unable to reach silica surfaces through resist sidewalls with a depth of 40 nm. The break-through etching of a hard mask sacrifice Cr layer with a thickness of 5 nm by Ar ion milling and the subsequent inductively coupled plasma etching of silica enabled the fabrication of silica hole templates with diameters of 7–20 nm and depths of 20–30 nm.

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Section: Introductionmentioning

confidence: 99%

Silica imprint templates with concave patterns from single-digit nanometers fabricated by electron beam lithography involving argon ion beam milling

Ito

Kikuchi

Watanabe³

et al. 2017

Jpn. J. Appl. Phys.

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“…The main obstacle for preparing hard molds with a high-resolution is the process complexity. Such fine-structured master molds are usually amenable to fabrication using special micro-machining technology such as EBL and self-aligned double patterning [28][29][30]. NIL technology itself is a simple and inexpensive bottom-up technique, nevertheless it has not been able to avoid the top-down process in the preparation of hard molds with well-resolved patterns.…”

Section: Introductionmentioning

confidence: 99%

Simple and scalable preparation of master mold for nanoimprint lithography

et al. 2017

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Nanoimprint lithography (NIL) is one of the most prominent bottom-up techniques for duplicating nanostructures with a high throughput. However, fabrication of starting master mold commonly requires expensive equipment of top-down techniques, or additional steps to transfer the fabricated patterns from bottom-up methods. Here we demonstrate that a SiO nanostructure manufactured from a self-assembled block copolymer, polystyrene-b-polydimethylsiloxane (PS-b-PDMS), directly serves as a master mold for NIL without further modification. A hexagonally aligned pattern over the entire substrate is established using a simple technique; solvent annealing and etching. Etching also plays an important role in endowing fluorine on the surface of SiO, thus promoting smooth demolding upon imprinting. The obtained pattern of the SiO nanostructure is transferred to a polymer surface using UV nanoimprint. Identical patterns of the SiO nanostructure are elaborately reproduced on Ni and Cu nanodot arrays via electroplating on the polymer transcript, which was verified by morphological observations. The uniformity of the replicated Ni nanodot array is evaluated using spectroscopic ellipsometry. The measured optical response of the Ni nanodot is validated by electromagnetically simulated results, indicating that the pattern transfer is not limited to a small local area. In addition, the durability of the SiO mold pattern is corroborated after the imprinting process, thus guaranteeing the reusability of the fabricated nanostructure as a master mold. The proposed approach does not require any high-end lithographic techniques; this may result in significant cost and time reductions in future nanofabrication.

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“…It was shown that 12-nm-hp L=S and 22-nm-bp hole patterns were realized to have the highest resolution. [22][23][24][25] In this paper, we describe the feasibility of nanopatterning on quartz substrates using R-θ EBL, RIE, and NIL for future BPM and permanent memory applications, in which we study the hole patterning of a circular band on quartz by R-θ EBL followed by RIE, and then dot patterning on quartz using NIL replication followed by RIE. In an actual memory application, the R-θ patterning on the circular band will be necessary; thus, this study is useful for estimating the feasibility of nanopatterning for future memory applications.…”

Section: Introductionmentioning

confidence: 99%

Nanohole and dot patterning processes on quartz substrate by R–θ electron beam lithography and nanoimprinting

Watanabe¹,

Taniguchi²,

Suzuki³

et al. 2016

Jpn. J. Appl. Phys.

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Fine hole and dot patterns with bit pitches (bp’s) of less than 40 nm were fabricated in the circular band area of a quartz substrate by R–θ electron beam lithography (EBL), reactive ion etching (RIE), and nanoimprinting. These patterning processes were studied to obtain minimum pitch sizes of hole and dot patterns without pattern collapse. The patterning on the circular band was aimed to apply these patterning processes to future high-density bit-patterned media (BPM) for hard disk drive (HDD) and permanent memory for the long life archiving of digital data. In hole patterning, a minimum-22-nm-bp and 8.2-nm-diameter pattern (1.3 Tbit/in.2) was obtained on a quartz substrate by optimizing the R–θ EBL and RIE processes. Dot patterns were replicated on another quartz substrate by nanoimprinting using a hole-patterned quartz substrate as a master mold followed by RIE. In dot patterning, a minimum-30-nm-bp and 18.5-nm-diameter pattern (0.7 Tbit/in.2) was obtained by introducing new descum conditions. It was observed that the minimum bp of successful patterning increased as the fabrication process proceeded, i.e., from 20 nm bp in the first EBL process to 30 nm bp in the last quartz dot patterning process. From the measured diameters of the patterns, it was revealed that pattern collapse was apt to occur when the value of average diameter plus 3 sigma of diameter was close to the bp. It was suggested that multiple fabrication processes caused the degradation of pattern quality; therefore, hole patterning is more suitable than dot patterning for future applications owing to the lower quality degradation by its simple fabrication process.

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A master-mold fabrication by electron beam lithography followed by nanoimprinting and self-aligned double patterning

Cited by 4 publications

References 28 publications

Silica imprint templates with concave patterns from single-digit nanometers fabricated by electron beam lithography involving argon ion beam milling

Silica imprint templates with concave patterns from single-digit nanometers fabricated by electron beam lithography involving argon ion beam milling

Simple and scalable preparation of master mold for nanoimprint lithography

Nanohole and dot patterning processes on quartz substrate by R–θ electron beam lithography and nanoimprinting

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