| 1. |
- Etula, Jarkko, et al.
(författare)
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Carbon nanotube membranes for EUV photolithography-a versatile material platform
- 2023
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Ingår i: International Conference on Extreme Ultraviolet Lithography 2023. - 9781510667488
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Konferensbidrag (refereegranskat)abstract
- Next generation of high-NA extreme ultraviolet (EUV) photolithography introduces higher power levels and faster reticle accelerations, enabling breakthrough in scanner efficiency. This results in higher temperatures and mechanical stresses on the EUV pellicles. Here we demonstrate scalable carbon nanotube (CNT) membrane mass production from a floating catalyst chemical vapor deposition (FC-CVD) reactor, using a direct dry deposition method. This direct high volume fabrication method yields highly uniform CNT networks with high strength and purity, enabling exceedingly thin CNT pellicles with high transparency at EUV. This end-To-end manufacturing process, starting from reagent gases, enables control and reproducibility over the final nanomaterial product. Control over synthesis allows tailoring of the carbon nanotube diameter and wall count (SWCNT or FWCNT), as well as control over the CNT network morphology such as the density, bundle size, and orientation of CNTs. The combination of this direct fabrication method with the exceptional mechanical and thermal properties of CNTs creates a versatile membrane platform, which can be further modified with post process steps such as purification to remove metal impurities. To enable conformal and thin coatings on CNTs, wet and dry functionalization steps are demonstrated to match the surface chemistry of CNTs to the specific deposition chemistry used in atomic layer (ALD), chemical vapor (CVD), or physical vapor (PVD) deposition processes. Thicker and denser CNT membranes with appropriate coatings are also suitable for other roles, such as filtering debris from an EUV source, blocking DUV photons and electrons, and providing a gas seal for differential pressure.
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| 2. |
- Etula, Jarkko, et al.
(författare)
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Room-Temperature Micropillar Growth of Lithium-Titanate-Carbon Composite Structures by Self-Biased Direct Current Magnetron Sputtering for Lithium Ion Microbatteries
- 2019
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Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 29:42
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Tidskriftsartikel (refereegranskat)abstract
- Here, an unidentified type of micropillar growth is described at room temperature during conventional direct-current magnetron sputtering (DC-MS) deposition from a Li4Ti5O12+graphite sputter target under negative substrate bias and high operating pressure. These fabricated carbon-Li2O-TiO2 microstructures consisting of various Li4Ti5O12/Li2TiO3/LixTiO2 crystalline phases are demonstrated as an anode material in Li-ion microbatteries. The described micropillar fabrication method is a low-cost, substrate independent, single-step, room-temperature vacuum process utilizing a mature industrial complementary metal-oxide-semiconductor (CMOS)-compatible technology. Furthermore, tentative consideration is given to the effects of selected deposition parameters and the growth process, as based on extensive physical and chemical characterization. Additional studies are, however, required to understand the exact processes and interactions that form the micropillars. If this facile method is further extended to other similar metal oxide-carbon systems, it could offer alternative low-cost fabrication routes for microporous high-surface area materials in electrochemistry and microelectronics.
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| 3. |
- Grimm, Alejandro, et al.
(författare)
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Slagging and fouling characteristics during co-combustion of Scots pine bark with low-temperature dried pulp and paper mill chemical sludge
- 2019
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Ingår i: Fuel processing technology. - : Elsevier. - 0378-3820 .- 1873-7188. ; 193, s. 282-294
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Tidskriftsartikel (refereegranskat)abstract
- This paper shows how chemical sludge (CS) generated during wastewater treatment at a paperboard mill can be quickly dried at low-temperature and employed in bark-fired boilers to reduce slagging and corrosion problems. By using a cyclone-dryer operated at an inlet-air velocity of 110 m/s and a temperature of 90 degrees C, the dry-matter content of CS was increased from approximately 19 to 82%. The residence time of CS inside the cyclone was approximately 2 s when using the inlet-air velocity mentioned above. Disaggregation of the feedstock caused by collisions with the cyclone wall and between particles played a crucial role in enhancing the efficiency of heat and mass transfer. Three co-pelletized mixtures of Scots pine bark (SPB) and dried-CS were combusted in a 40 kW fixed-bed burner. Flue gas analysis was performed with a gas analyser. Coarse and fine ash were analysed by SEM-EDS and XRD. NOx, and SO2 emissions increased with increasing amount of CS in the mixtures. Mono combustion of SPB resulted in a large quantity of slag (i.e., molten ash) with a high degree of sintering (i.e., hardness of the slag), and ash deposits formed on heat transfer surfaces were rich in K2SO4 and KCI. Mixtures of SPB and CS were less prone to slagging, and the amount of alkali chloride in the deposits was reduced in favour of alkali sulphate formation.
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