| 51. |
- Maximov, Ivan, et al.
(författare)
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Fabrication of Si-based nanoimprint stamps with sub-20 nm features
- 2002
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Ingår i: MICROELECTRONIC ENGINEERING. - 1873-5568 .- 0167-9317. ; 61-2, s. 449-454
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Konferensbidrag (refereegranskat)abstract
- We present two alternative methods for fabrication of nanoimprint lithography stamps in SiO2 with sub-20 nm features: (a) optimized electron beam lithography (EBL) and lift-off patterning of a 15-nm thick Cr mask, and (b) aerosol deposition of W particles in the 20-nm size range. In both cases, the pattern transfer into SiO2 was performed using reactive ion etching (RIE) with CHF3 as etch gas. In the first approach, we used a double layer resist system (PMMA/ZEP 520A7 positive resists) for the EBL exposure. Resist thickness, exposure dose and development time were optimized to obtain 15-20 nm features after Cr lift-off. In the second approach, we used size selected W aerosol particles as etch masks during etching of SiO2. Both methods of stamp fabrication are compared and discussed. (C) 2002 Published by Elsevier Science B.V.
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| 52. |
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| 53. |
- Maximov, Ivan, et al.
(författare)
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Investigation of polymethylmethacrylate resist residues using photoelectron microscopy
- 2002
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Ingår i: Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures. - : American Vacuum Society. - 1071-1023 .- 1520-8567 .- 0734-211X. ; 20:3, s. 1139-1142
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Konferensbidrag (refereegranskat)abstract
- Quantitative photoelectron spectromicroscopy has been used to study polymethylmethacrylate (PMMA) resist residues on SiO2 surfaces after electron beam exposure and resist development, It was found that correctly exposed and developed PMMA leaves residues with an average thickness of about 1 nm. Higher exposure doses result in the decrease in film thickness, but with residues of about 0.5 mn. The technique can be applied as a powerful tool for surface and interface quality control in technology of electronic devices.
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| 54. |
- Maximov, Ivan, et al.
(författare)
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New high resolution negative resist mr-L 6000.1 XP for electron beam and nanoimprint lithography
- 2002
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Ingår i: 7th International Conference on Nanometer-Scale Science and Technology and 21st European Conference on Surface Science.
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Konferensbidrag (refereegranskat)abstract
- We present the characterization results of a new high resolution negative electron beam resist mr-L 6000.1 XP. The resist can also be used as imprintable polymer in nanoimprint lithography with sub-100 nm resolution. The feature size achieved after e-beam exposure was about 50 nm with sensitivity of 2-4 μC/cm2. Studies of the resist properties as a function of chemical composition and development conditions are also presented
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| 55. |
- Meng, Fantao, et al.
(författare)
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Efficient methods of nanoimprint stamp cleaning based on imprint self-cleaning effect.
- 2011
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 22:18
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Tidskriftsartikel (refereegranskat)abstract
- Nanoimprint lithography (NIL) is a nonconventional lithographic technique that promises low-cost, high-throughput patterning of structures with sub-10 nm resolution. Contamination of nanoimprint stamps is one of the key obstacles to industrialize the NIL technology. Here, we report two efficient approaches for removal of typical contamination of particles and residual resist from stamps: thermal and ultraviolet (UV) imprinting cleaning-both based on the self-cleaning effect of imprinting process. The contaminated stamps were imprinted onto polymer substrates and after demolding, they were treated with an organic solvent. The images of the stamp before and after the cleaning processes show that the two cleaning approaches can effectively remove contamination from stamps without destroying the stamp structures. The contact angles of the stamp before and after the cleaning processes indicate that the cleaning methods do not significantly degrade the anti-sticking layer. The cleaning processes reported in this work could also be used for substrate cleaning.
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| 56. |
- Meng, Fantao, et al.
(författare)
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Fabrication and characterization of bilayer metal wire-grid polarizer using nanoimprint lithography on flexible plastic substrate
- 2011
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Ingår i: Microelectronic Engineering. - : Elsevier BV. - 1873-5568 .- 0167-9317. ; 88:10, s. 3108-3112
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we demonstrate the fabrication of bilayer metal wire-grid polarizers and the characterization of their performance. The polarizers with 200 nm period were fabricated on flexible plastic substrates by nanoimprint lithography (NIL), followed by aluminum deposition. Transmission efficiency over 0.51 and extinction ratio higher than 950 can be achieved in the visible range when the aluminum thickness of the polarizer is 100 nm. The fabrication process only involves direct imprinting on flexible plastic substrates and aluminum deposition, without any resist spin-coating, lift-off, and etching processes, which is much simpler, less costly, and applicable to large volume production. (C) 2011 Elsevier B.V. All rights reserved.
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| 57. |
- Meng, Fantao, et al.
(författare)
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Nonlinear electrical properties of Si three-terminal junction devices
- 2010
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 97:24
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Tidskriftsartikel (refereegranskat)abstract
- This letter reports on the realization and characterization of silicon three-terminal junction devices made in a silicon-on-insulator wafer. Room temperature electrical measurements show that the fabricated devices exhibit pronounced nonlinear electrical properties inherent to ballistic electron transport in a three-terminal ballistic junction (TBJ) device. The results show that room temperature functional TBJ devices can be realized in a semiconductor material other than high-mobility III-V semiconductor heterostructures and provide a simple design principle for compact silicon devices in nanoelectronics. (C) 2010 American Institute of Physics. [doi:10.1063/1.3526725]
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| 58. |
- Moltu, Sissel J., et al.
(författare)
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Arachidonic and docosahexaenoic acid supplementation and brain maturation in preterm infants : a double blind RCT
- 2024
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Ingår i: Clinical Nutrition. - : Elsevier. - 0261-5614 .- 1532-1983. ; 43:1, s. 176-186
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Tidskriftsartikel (refereegranskat)abstract
- Background: Arachidonic acid (ARA) and docosahexaenoic acid (DHA) are important structural components of neural cellular membranes and possess anti-inflammatory properties. Very preterm infants are deprived of the enhanced placental supply of these fatty acids, but the benefit of postnatal supplementation on brain development is uncertain. The aim of this study was to test the hypothesis that early enteral supplementation with ARA and DHA in preterm infants improves white matter (WM) microstructure assessed by diffusion-weighted MRI at term equivalent age.Methods: In this double-blind, randomized controlled trial, infants born before 29 weeks gestational age were allocated to either 100 mg/kg ARA and 50 mg/kg DHA (ARA:DHA group) or medium chain triglycerides (control). Supplements were started on the second day of life and provided until 36 weeks postmenstrual age. The primary outcome was brain maturation assessed by diffusion tensor imaging (DTI) using Tract-Based Spatial Statistics (TBSS) analysis.Results: We included 120 infants (60 per group) in the trial; mean (range) gestational age was 26+3 (22+6 - 28+6) weeks and postmenstrual age at scan was 41+3 (39+1 - 47+0) weeks. Ninety-two infants underwent MRI imaging, and of these, 90 had successful T1/T2 weighted MR images and 74 had DTI data of acceptable quality. TBSS did not show significant differences in mean or axial diffusivity between the groups, but demonstrated significantly higher fractional anisotropy in several large WM tracts in the ARA:DHA group, including corpus callosum, the anterior and posterior limb of the internal capsula, inferior occipitofrontal fasciculus, uncinate fasciculus, and the inferior longitudinal fasciculus. Radial diffusivity was also significantly lower in several of the same WM tracts in the ARA:DHA group.Conclusion: This study suggests that supplementation with ARA and DHA at doses matching estimated fetal accretion rates improves WM maturation compared to control treatment, but further studies are needed to ascertain any functional benefit.Clinical trial registration: www.clinicaltrials.gov; ID:NCT03555019.
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| 59. |
- Montelius, Lars, et al.
(författare)
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Next generation nanotechnologies for sensor array fabrication
- 2002
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Ingår i: 7th International Conference on Nanometer-Scale Science and Technology and 21st European Conference on Surface Science.
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Konferensbidrag (refereegranskat)abstract
- New emerging technologies such as nanoimprint lithography (NIL) offers the biosensor research community the possibility to fabricate low-cost biodevices having nanometer dimensions. Such nanosized devices can be applied as biosensors where new functions might emerge due to the nanoscale dimensions. In this paper we will discuss various nanolithography methods as well as the benefits of going to the nanoscale for biosensor applications. We will also show results from mixed NIL and UV-lithography for fabrication of interdigitated nanobiosensor electrodes on up to 6'' large Si wafers. The electrode and inter-electrode distances were 100 nm wide over a total area of 200 μm×200 μm. We will also show the obtained enhanced efficiency of redox-recycling when utilizing such nanoscaled biosensors
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| 60. |
- Otnes, Gaute, et al.
(författare)
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Strategies to obtain pattern fidelity in nanowire growth from large-area surfaces patterned using nanoimprint lithography
- 2016
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Ingår i: Nano Research. - : Springer Science and Business Media LLC. - 1998-0124 .- 1998-0000. ; 9:10, s. 2852-2861
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Tidskriftsartikel (refereegranskat)abstract
- Position controlled nanowire growth is important for nanowire-based optoelectronic components which rely on light emission or light absorption. For solar energy harvesting applications, dense arrays of nanowires are needed; however, a major obstacle to obtaining dense nanowire arrays is seed particle displacement and coalescing during the annealing stage prior to nanowire growth. Here, we explore three different strategies to improve pattern preservation of large-area catalyst particle arrays defined by nanoimprint lithography for nanowire growth. First, we see that heat treating the growth substrate prior to nanoimprint lithography improves pattern preservation. Second, we explore the possibility of improving pattern preservation by fixing the seed particles in place prior to annealing by modifying the growth procedure. And third, we show that a SiNx growth mask can fully prevent seed particle displacement. We show how these strategies allow us to greatly improve the pattern fidelity of grown InP nanowire arrays with dimensions suitable for solar cell applications, ultimately achieving 100% pattern preservation over the sampled area. The generic nature of these strategies is supported through the synthesis of GaAs and GaP nanowires. [Figure not available: see fulltext.]
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