Defect reduction progress in step and flash imprint lithography

Selenidis, K.; Maltabes, John G.; McMackin, Ian; Perez, Joseph; Martin, W.; Resnick, D. J.; Sreenivasan, S. V.

doi:10.1117/12.747565

Cited by 38 publications

(14 citation statements)

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“…In this study, a novel technique, taking advantage of efficient hydroxyl radical reaction with organics, is demonstrated for template resist removal and the influences of MegaSonic treatment on pattern structure integrity and particle removal effectiveness is also investigated. Nearly all published work on template cleaning to-date has focused on 65mm square (1/4" thick) templates [3][4][5][6]. In this paper automated acid-free cleaning on 6" round (0.5mm thick) templates is demonstrated.…”

Section: Introductionmentioning

confidence: 95%

Advanced cleaning of nano-imprint lithography template in patterned media applications

Singh¹,

Chen²,

Dress³

et al. 2010

SPIE Proceedings

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As the magnetic storage industry roadmap calls for aggressive terabit/in 2 densities over the next few years, the shift from the current planar media to patterned media; grooved surfaces (discrete track media / DTM) and/or individually defined magnetic dots (bit patterned media / BPM), will be necessary. Both types of patterned media require lithography to produce the pattern on the disk and the most promising lithography candidate today is nano-imprint lithography (NIL). During the imprinting process a thin, round, transparent template made of quartz is functioned as a mold to inversely transfer the features from its surface to the patterning medium on the disks by direct contact. One issue with this technique is the high probability of defects due to repeated contact of the template with the resist before, during, and after UV radiation. Defect management through template cleaning, inspection and defect characterization is critical to preserve integrity of the process. In this paper, advanced acid-free cleaning combined with MegaSonic treatment for defect elimination is investigated for effectiveness on discrete track recording (DTR) and BPM patterned templates. For the experiments, templates containing 250KTPI (100nm track pitch) full surface DTR pattern, 450 KTPI (56nm track pitch) with narrow band DTR pattern, and 250Gdpsi (50nm track pitch) with narrow band BPM pattern are used. The effect of MegaSonic cleaning on the pattern integrity of fragile features is studied. General characterization of defect attributes is made feasible through a series of imprinting and template cleaning cycles focused on resist residues and contaminant removal. Imprinted disks are analyzed using Candela disk inspection and SEM imaging of the pattern. Template cleaning is performed using HamaTech MaskTrack TeraPure automated template cleaning system.

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Section: Introductionmentioning

confidence: 95%

Advanced cleaning of nano-imprint lithography template in patterned media applications

Singh¹,

Chen²,

Dress³

et al. 2010

SPIE Proceedings

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“…1,2 Imprint process failure can cause the cross-linked resist to stick to the template which can produce poor quality imprints with low yield and throughput. 3 The resulting contaminants are resistant to solvent attack, thus, their removal requires the use of cleaning processes with aggressive oxidants and physical force particle removal techniques, such as MegaSonic. Considering that multiple cleanings will be performed on the template during its lifetime, the issue of template damage in such an environment should be carefully addressed.…”

Section: Introductionmentioning

confidence: 99%

Cleaning induced imprint template erosion

Singh

Wähler³

et al. 2012

J. Micro/Nanolith. MEMS MOEMS

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We studied the erosion and feature stability of fused silica patterns under different template cleaning conditions. The conventional sulfuric acid and hydrogen peroxide mixture (SPM) cleaning is compared with an advanced nonacid process. Spectroscopic ellipsometry optical critical dimension measurements were used to characterize the changes in pattern profile with good sensitivity. This study confirmed the erosion of the silica patterns in the traditional acid-based SPM cleaning mixture (H 2 SO 4 þ H 2 O 2 ) at a rate of ∼0.1 nm per cleaning cycle. However, the advanced nonacid cleaning process only showed critical dimension shift of ∼0.01 nm per cleaning. Contamination removal and pattern integrity of sensitive 20-nm features under MegaSonic assisted cleaning was also demonstrated.

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“…In the UV-imprint process, a silica template with the desired pattern is in direct contact with the resist when UVirradiation is applied to cure the resist [1,2]. Imprint process failure can cause the cross-linked resist to stick to the template which can produce poor quality imprints with low yield and throughput [3]. The resulting contaminants are resistant to solvent attack, thus, their removal requires the use of cleaning processes with aggressive oxidants and physical force particle removal techniques such as MegaSonic.…”

Section: Introductionmentioning

confidence: 99%

Controlling template erosion with advanced cleaning methods

Singh

Wähler³

et al. 2012

Alternative Lithographic Technologies IV

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We studied the erosion and feature stability of fused silica patterns under different template cleaning conditions. The conventional SPM cleaning is compared with an advanced non-acid process. Spectroscopic ellipsometry optical critical dimension (SE-OCD) measurements were used to characterize the changes in pattern profile with good sensitivity. This study confirmed the erosion of the silica patterns in the traditional acid-based SPM cleaning mixture (H2SO4+H2O2) at a rate of ~0.1nm per cleaning cycle. The advanced non-acid clean process however only showed CD shift of ~0.01nm per clean. Contamination removal & pattern integrity of sensitive 20nm features under MegaSonic assisted cleaning is also demonstrated.

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Defect reduction progress in step and flash imprint lithography

Cited by 38 publications

References 0 publications

Advanced cleaning of nano-imprint lithography template in patterned media applications

Advanced cleaning of nano-imprint lithography template in patterned media applications

Cleaning induced imprint template erosion

Controlling template erosion with advanced cleaning methods

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