| 1. |
- 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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| 2. |
- Asif, Muhammad, et al.
(författare)
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Comparison of UV-curable materials for high-resolution polymer nanoimprint stamps
- 2022
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Ingår i: Micro and Nano Engineering. - : Elsevier BV. - 2590-0072. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- We present a systematic comparison of four resins for nanoimprint intermediate polymer stamps, the standard IPS material, OrmoStamp and two new polymers GMN-PS90 (foil) and GMN-PS40 (liquid). The new polymers are based on acrylated silane and offer sufficiently high Young’s modulus and low shrinkage to provide good me chanical stability during the imprint process of well-separated structures. No anti-sticking treatment requires for those new polymers and they can be used at room temperature, which results in better stability of the nano imprint process. The nanoimprint experiments using four resins showed a superior performance of the GMNPS90 material in both single-layer and double-layer imprint process with resolution after lift-off about 30 nm.
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| 3. |
- Gómez, Víctor J., et al.
(författare)
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Wafer-scale nanofabrication of sub-100 nm arrays by deep-UV displacement Talbot lithography
- 2020
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 31:29
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Tidskriftsartikel (refereegranskat)abstract
- In this manuscript, we demonstrate the potential of replacing the standard bottom anti-reflective coating (BARC) with a polymethylglutarimide (PMGI) layer for wafer-scale nanofabrication by means of deep-UV displacement talbot lithography (DTL). PMGI is functioning as a developable non-UV sensitive bottom anti-reflective coating (DBARC). After introducing the fabrication process using a standard BARC-based coating and the novel PMGI-based one, the DTL nanopatterning capabilities for both coatings are compared by means of the fabrication of etched nanoholes in a dielectric layer and metal nanodots made by lift-off. Improvement of DTL capabilities are attributed to a reduction of process complexity by avoiding the use of O2 plasma etching of the BARC layer. We show the capacity of this approach to produce nanoholes or nanodots with diameters ranging from 95 to 200 nm at a wafer-scale using only one mask and a proper exposing dose. The minimum diameter of the nanoholes is reduced from 118 to 95 nm when using the PMGI-based coating instead of the BARC-based one. The possibilities opened by the PMGI-based coating are illustrated by the successful fabrication of an array of nanoholes with sub-100 nm diameter for GaAs nanowire growth on a 2″ GaAs wafer, a 2″ nanoimprint lithography (NIL) master stamp, and an array of Au nanodots made by lift-off on a 4″ silica wafer. Therefore, DTL possess the potential for wafer-scale manufacturing of nano-engineered materials.
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| 4. |
- Graczyk, Mariusz, et al.
(författare)
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Fabrication of bottle-shaped nanochannels in fused silica using a self-closing effect
- 2012
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Ingår i: Microelectronic Engineering. - : Elsevier BV. - 1873-5568 .- 0167-9317. ; 97, s. 173-176
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Tidskriftsartikel (refereegranskat)abstract
- The spatial control of molecular motor function, using nanostructured surfaces, is of great interest for the development of commercial devices for diagnostics and high-throughput drug screening with molecular motors as targets. In the present study we have fabricated 100-300 nm wide nanochannels, completely subsurfaced on fused silica chips, with the aim to interface them with a microfluidic system. Such a system will allow for changes in the chemical environment surrounding molecular motors, with minimal influence on their directional motion. This will be achieved by changing the chemical environment in a perpendicular direction to the motor motion and allowing the chemical substances to diffuse in and out of the nanochannels via a small slit (5-10 nm) on the top of the nanochannels. To create this slit, and to control its width, we here demonstrate the use of a self-closing effect based on the volume increase (2.27 times) during oxidation of silicon. The details of the fabrication steps (EBL, RIE and oxidation) are discussed. (C) 2012 Elsevier B.V. All rights reserved.
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| 5. |
- Graczyk, Mariusz, et al.
(författare)
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Nanoimprint stamps with ultra-high resolution : Optimal fabrication techniques
- 2018
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Ingår i: Microelectronic Engineering. - : Elsevier BV. - 0167-9317. ; 190, s. 73-78
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Tidskriftsartikel (refereegranskat)abstract
- Single-digit nanometer patterning by nanoimprint lithography is a challenging task, which requires optimum stamp fabrication technique. In the current work, we present different strategies for technology of hard master stamps to make intermediate working stamps with sub-10 nm features. Methods of both negative and positive master stamps fabrication, based on EBL, RIE and ALD are described and compared. A single-step copying of negative master stamps using a polymer material is a preferred strategy to reach the ultra high-resolution. Lines as small as 5.6 nm are demonstrated in a resist using a combined thermal and UV-imprint with OrmoStamp material as a working stamp.
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| 6. |
- Graczyk, Mariusz, et al.
(författare)
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Optimization of a self-closing effect to produce nanochannels with top slits in fused silica
- 2012
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Ingår i: Journal of Vacuum Science and Technology B. - : American Vacuum Society. - 1520-8567. ; 30:6
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Tidskriftsartikel (refereegranskat)abstract
- The authors report on the fabrication of subsurfaced 100-600 nm wide nanochannels in fused silica with top slit openings in the size range of 5-10 nm. Such nanochannels can be used in combination with a nanofluidics system to guide molecular motors and quickly switch the chemical environment inside the nanochannels through diffusion via the top slits. To realize nanochannel top slits in this size range, the authors here demonstrate the use of a self-closing effect based on the volume expansion of a thin Si layer during oxidation. A high contrast electron beam lithography exposure step in conjunction with dry etching of SiO2 by reactive ion etching (RIE) and Si by inductively coupled plasma-RIE followed by wet etching of a fused silica substrate is used to create the initial slit before oxidation. The details of nanochannel fabrication steps are described and discussed. (C) 2012 American Vacuum Society. [http://dx.doi.org/10.1116/1.4766317]
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| 7. |
- Jafari Jam, Reza, et al.
(författare)
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III-V nanowire synthesis by use of electrodeposited gold particles
- 2015
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Ingår i: Nano letters (Print). - Washington, DC : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 15:1, s. 134-138
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Tidskriftsartikel (refereegranskat)abstract
- Semiconductor nanowires are great candidates for building novel electronic devices. Considering the cost of fabricating such devices, substrate reuse and gold consumption are the main concerns. Here we report on implementation of high throughput gold electrodeposition for selective deposition of metal seed particles in arrays defined by lithography for nanowire synthesis. By use of this method, a reduction in gold consumption by a factor of at least 300 was achieved, as compared to conventional thermal evaporation for the same pattern. Because this method also facilitates substrate reuse, a significantly reduced cost of the final device is expected. We investigate the morphology, crystallography, and optical properties of InP and GaAs nanowires grown from electrodeposited gold seed particles and compare them with the properties of nanowires grown from seed particles defined by thermal evaporation of gold. We find that nanowire synthesis, as well as the material properties of the grown nanowires are comparable and quite independent of the gold deposition technique. On the basis of these results, electrodeposition is proposed as a key technology for large-scale fabrication of nanowire-based devices.
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| 8. |
- Joensson, C T, et al.
(författare)
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Synthesis and characterization of cobalt silicide films on silicon
- 2006
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Ingår i: Ion Beam Analysis - Proceedings of the Seventeenth International Conference on Ion Beam Analysis (Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms). - : Elsevier BV. - 0168-583X. ; 249, s. 532-535
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Konferensbidrag (refereegranskat)abstract
- Cobalt silicide has emerged as a leading contact material in silicon technology due to its low resistivity, high stability and small lattice mismatch. In this study, 0.2-0.4 mu m thick Co films were deposited on Si(100) wafers by RF magnetron sputtering at room temperature, and annealed at temperatures from 600 to 900 degrees C in vacuum. As-deposited and annealed samples were characterized by Rutherford backscattering spectrometry (RBS), nuclear reaction analysis (NRA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Although the Si substrates were sputter cleaned before the deposition, all the samples showed a thin oxide layer at the Si/Co interfaces. Annealing up to 700 degrees C did not alter the composition at the interface except small amount Co diffusion into Si. Annealing at 800 degrees C promotes the evaporation of the oxides from the interface and, as a result, clean CoSi2 films were formed. Although the interface appeared to be sharp within the RBS resolution after high temperature annealing, the surface topography was relatively rough with varying size of crystal grains. (c) 2006 Elsevier B.V. All rights reserved.
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| 9. |
- Khan, Sabbir Ahmed, et al.
(författare)
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High-Definition Nanoimprint Stamp Fabrication by Atomic Layer Etching
- 2018
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; , s. 2476-2482
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: Nanoimprint lithography (NIL) has the potential for low-cost andhigh-throughput nanoscale fabrication. However, the NIL quality and resolution areusually limited by the shape and size of the nanoimprint stamp features. Atomiclayer etching (ALE) can provide a damage-free pattern transfer with ultimate etchcontrol for features of all length scales, down to the atomic scale, and for all featuregeometries, which is required for good quality and high-resolution nanoimprintstamp fabrication. Here, we present an ALE process for nanoscale pattern transferand high-resolution nanoimprint stamp preparation. This ALE process is based onchemical adsorption of a monoatomic layer of dichloride (Cl2) on the siliconsurface, followed by the removal of a monolayer of Cl2-modified silicon by argonbombardment. The nanopatterns of different geometries, loadings, and pitcheswere fabricated by electron beam lithography on a silicon wafer, and ALE wassubsequently performed for pattern transfer using a resist as an etch mask. Thepost-ALE patterns allowed us to study the different effects and limitations of theprocess, such as trenching and sidewall tapering. The ALE-processed silicon wafers were used as hard nanoimprint stamps in a thermal nanoimprint process. Features as small as 30 nm were successfully transferred into a poly(methyl methacrylate) layer, which demonstrated the great potential of ALE in fabricating nanoimprint stamps with ultrahigh resolution.
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| 10. |
- Lindberg, Frida W., et al.
(författare)
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Design and development of nanoimprint-enabled structures for molecular motor devices
- 2019
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Ingår i: Materials Research Express. - : IOP Publishing. - 2053-1591. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- Devices based on molecular motor-driven cytoskeletal filaments, e.g., actin filaments, have been developed both for biosensing and biocomputational applications. Commonly, these devices require nanoscaled tracks for guidance of the actin filaments which has limited the patterning technique to electron beam lithography. Thus, large scale systems become intractable to fabricate at a high throughput within a reasonable time-frame. We have studied the possibility to fabricate molecular motor-based devices using the high throughput, high resolution technique of nanoimprint lithography. Molecular motor-based devices require wide open regions (loading zones) to allow filaments to land for later propulsion into the nanoscale tracks. Such open zones are challenging to fabricate using nanoimprint lithography due to the large amount of material displaced in the process. We found that this challenge can be overcome by introducing nanoscaled pillars inside the loading zones, into which material can be displaced during imprint. By optimising the resist thickness, we were able to decrease the amount of material displaced without suffering from insufficient filling of the stamp. Furthermore, simulations suggest that the shape and positioning of the pillars can be used to tailor the overall cytoskeletal filament transportation direction and behaviour. This is a potentially promising design feature for future applications that however, requires further optimisations before experimental realisation.
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