| 1. |
- Abermann, S., et al.
(författare)
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Processing and evaluation of metal gate/high-k/Si capacitors incorporating Al, Ni, TiN, and Mo as metal gate, and ZrO2 and HfO2 as high-k dielectric
- 2007
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Ingår i: Microelectronic Engineering. - : Elsevier BV. - 0167-9317 .- 1873-5568. ; 84:5-8, s. 1635-1638
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Tidskriftsartikel (refereegranskat)abstract
- We evaluate various metal gate/high-k/Si capacitors by their resulting electrical characteristics. Therefore, we process MOS gate stacks incorporating aluminium (Al), nickel (Ni), titanium-nitride (TiN), and molybdenum (Mo) as the gate material, and metal organic chemical vapour deposited (MOCVD) ZrO2 and HfO2 as the gate dielectric, respectively. The influence of the processing sequence - especially of the thermal annealing treatment - on the electrical characteristics of the various gate stacks is being investigated. Whereas post metallization annealing in forming gas atmosphere improves capacitance-voltage behaviour (due to reduced interface-, and oxide charge density), current-voltage characteristics degrade due to a higher leakage current after thermal treatment at higher temperatures. The Flatband-voltage values for the TiN-, Mo-, and Ni-capacitors indicate mid-gap pinning of the metal gates, however, Ni seems to be thermally unstable on ZrO2, at least within the process scheme we applied.
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| 2. |
- Abermann, S., et al.
(författare)
-
Processing and evaluation of metal gate/high-kappa/Si capacitors incorporating Al, Ni, TiN, and Mo as metal gate, and ZrO2 and HfO2 as high-kappa dielectric
- 2007
-
Ingår i: Microelectronic Engineering. - : Elsevier BV. - 0167-9317 .- 1873-5568. ; 84:5-8, s. 1635-1638
-
Tidskriftsartikel (refereegranskat)abstract
- We evaluate various metal gate/high-K/Si capacitors by their resulting electrical characteristics. Therefore, we process MOS gate stacks incorporating aluminium (Al), nickel (Ni), titanium-nitride (TiN), and molybdenum (Mo) as the gate material, and metal organic chemical vapour deposited (MOCVD) ZrO2 and HfO2 as the gate dielectric, respectively. The influence of the processing sequence - especially of the thermal annealing treatment - on the electrical characteristics of the various gate stacks is being investigated. Whereas post metallization annealing in forming gas atmosphere improves capacitance-voltage behaviour (due to reduced interface-, and oxide charge density), current-voltage characteristics degrade due to a higher leakage current after thermal treatment at higher temperatures. The Flatband-voltage values for the TiN-, Mo-, and Ni-capacitors indicate mid-gap pinning of the metal gates, however, Ni seems to be thermally unstable on ZrO2, at least within the process scheme we applied.
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| 3. |
- Astromskas, Gvidas, et al.
(författare)
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Temperature and frequency characterization of InAs nanowire and HfO2 interface using capacitance-voltage method
- 2011
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Ingår i: Microelectronic Engineering. - : Elsevier BV. - 1873-5568 .- 0167-9317. ; 88:4, s. 444-447
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Konferensbidrag (refereegranskat)abstract
- InAs/HfO2 nanowire capacitors using capacitance-voltage (CV) measurements are investigated in the range of 10 kHz to 10 MHz. The capacitors are based on vertical nanowire arrays that are coated with an 8 nm-thick HfO2 layer by atomic layer deposition. CV characteristics are measured at temperatures in the range between -140 and 40 degrees C and the CV characteristics for nanowires with different Sn and Se n-type doping levels are compared. The comparison of the data at various doping levels points towards large number of traps for highly doped samples, caused by the preferential dopant precursor incorporation at the nanowire surface. We also evaluate the frequency dispersion of the accumulation capacitance and determine values below 2% with weak temperature dependence, indicating the existence of border traps in these nanowire capacitors. (C) 2010 Elsevier B.V. All rights reserved.
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| 4. |
- Auzelyte, Vaida, et al.
(författare)
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Exposure parameters for MeV proton beam writing on SU-8
- 2006
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Ingår i: Microelectronic Engineering. - : Elsevier BV. - 1873-5568 .- 0167-9317. ; 83:10, s. 2015-2020
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Tidskriftsartikel (refereegranskat)abstract
- Proton beam writing was performed on a lithographic resist to determine the main parameters required to achieve the minimum feature size, maximum pattern lateral density and maximum aspect ratio. A 2.5 MeV proton beam focused to sizes between 1.5 and 2.5 mu m was used to expose SU-8 negative resist. The number of protons per pixel was varied in the exposure of SU-8 with thicknesses between 5 and 95 pm. Patterns consisting of single pixels, single-pixel lines and multi-pixel areas with different densities were fabricated. The smallest structures achieved were posts 1.5 pin in diameter with 4:1 structure-space ratio in 15 pm thick resist and the highest aspect ratio structures of 20:1 in 40 pm resist were produced. It was found that the minimum feature size depended only on the beam size, and +/- 10% post size accuracy could be achieved within 40-70% variation of the number of protons. MeV proton beam allows a direct fabrication of complex shapes without a mask in single-step irradiation and. in addition, no proximity correction is needed. We present examples of MeV proton beam written single and multi-pixel microstructures with easily reproducible high aspect ratios and densities. (c) 2006 Elsevier B.V. All rights reserved.
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| 5. |
- Baus, M, et al.
(författare)
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Fabrication of monolithic bidirectional switch devices
- 2004
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Ingår i: Microelectronic Engineering. - 0167-9317 .- 1873-5568. ; 73-4, s. 463-467
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Tidskriftsartikel (refereegranskat)abstract
- The fabrication scheme of a novel MOS-based power device, a monolithic bidirectional switch (MBS), is presented. This concept allows the integration of a bidirectional switch with the advantages of low power consumption, small package size, and low fabrication costs. Furthermore, device simulations predict a performance benefit for power applications such as matrix converters. In an MBS, the field effect is used to control carrier concentrations in elevated structures made up of nearly intrinsic silicon. A CMOS-compatible nano-fabrication process for the MBS is proposed, employing local oxidation of silicon for self-aligned contact formation. First electrical results are presented. (C) 2004 Elsevier B.V. All rights reserved.
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| 6. |
- Beck, Marc, et al.
(författare)
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Improving stamps for 10 nm level wafer scale nanoimprint lithography
- 2002
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Ingår i: Microelectronic Engineering. - 1873-5568. ; 61-2, s. 441-448
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Tidskriftsartikel (refereegranskat)abstract
- The smaller the features on the stamp the more important are the interactions between stamp and polymer layer. A stamp rich in small structures will effectively show a surface area enlargement, which generally leads to adhesion of the polymer to the stamp. This makes a subsequent imprint impossible without troublesome and time-consuming cleaning. The anti-adhesion properties of Si- or SiO2-based stamps can be improved by binding fluorinated silanes covalently to the surface. In this paper, we demonstrate that the deposition procedure as well as the environment during deposition are important with respect to the quality and performance of the molecular layer. (C) 2002 Published by Elsevier Science B.V.
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| 7. |
- Beck, Marc, et al.
(författare)
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Nanoelectrochemical transducers for (bio-) chemical sensor applications fabricated by nanoimprint lithography
- 2004
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Ingår i: Microelectronic Engineering. - 1873-5568. ; 73-74, s. 837-842
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Tidskriftsartikel (refereegranskat)abstract
- Nanometer-structured transducers for commercial use in pharmaceutical, medical or (bio-) chemical analysis have so far been hardly accessible since they could not be produced by parallel lithography techniques at reasonable costs. We introduce here a method on. how to fabricate nanometer-structured interdigitated array electrodes including interconnections and bond pads in the micrometer range in a single imprint step on 2-in. wafer scale. The method enables the mass production of those devices at lowest cost opening a new field for the commercial use of nanometer-structured sensor systems.
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| 8. |
- Boström, Mathias, et al.
(författare)
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Temperature effects on the Casimir attraction between a pair of quantum wells
- 2000
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Ingår i: Microelectronic Engineering. - 0167-9317 .- 1873-5568. ; 51, s. 287-297
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Tidskriftsartikel (refereegranskat)abstract
- We present calculations of the free energy of attraction between two quantum wells in which the wells are treated as strictly two-dimensional metallic sheets. The van der Waals force exhibits fractional separation dependence in this system. This is in contrast to the usual integer separation dependence. We have performed numerical calculations at different temperatures and with different carrier densities. Except at very low temperatures thermal effects will be a dominating source of attraction. We have determined temperature criteria that must be fulfilled for the fractional separation dependence to be observable. Thermal corrections will be important already at temperatures less than 1 K. We further make some comments on a recent measurement of the Casimir force.
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| 9. |
- Bunk, Richard, et al.
(författare)
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Towards a 'nano-traffic' system powered by molecular motors
- 2003
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Ingår i: Microelectronic Engineering. - 1873-5568. ; 67-8, s. 899-904
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we reconstructed in vitro the behavior of two motor proteins-myosin and actin-responsible for the mechanical action of muscle cells. By transferring this in vivo system to an artificial environment, we were able to study the interaction between the proteins in more detail, as well as investigating the central mechanism of force production. Nm-patterning by e-beam lithography (EBL) could restore parts of the in vivo protein order, essential for potential nanotechnological applications. Much work was put into establishing the necessary compatibility between the biological and nano-lithographical processes. A range of EBL-resists were tested for protein compatibility. One particular kind (MRL-6000.1XP) supported good actin filament motility, while another (PMMA-950) behaved in the opposite way. Taking advantage of these findings, nm-sized lines were created in a double-layer structure of the two resists. The lines were found to act as binding sites for myosin, and as rectifying guides for the linearized motion of actin filaments. Velocities around 5 mum/s were measured. (C) 2003 Elsevier Science B.V. All rights reserved.
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| 10. |
- Carlberg, Patrick, et al.
(författare)
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Lift-off process for nanoimprint lithography
- 2003
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Ingår i: Microelectronic Engineering. - 1873-5568 .- 0167-9317. ; 67-8, s. 203-207
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Konferensbidrag (refereegranskat)abstract
- We report a novel a lift-off method for nanoimprint lithography. This is a bi-layer method, using a polymethyl methacrylate (PMMA) on lift-off layer (LOL) resist scheme. For the imprint step, direct evidence for good pattern transfer down to 20 nm is shown. Oxygen plasma ashing is required to remove residual PMMA. A liquid solvent, MF 319, is used to transfer the pattern down to the silicon. The LOL is dissolved isotropically while the PMMA is unaffected. Ashing time can kept to a minimum through the wet etch method. This reduces the line widening effect. After metal evaporation a two-step lift-off process prevents metal flakes from adhering to the surface electrostatically. At first warm acetone breakes apart the metal layer and dissolves the PMMA, then warm Remover S-1165 removes the LOL and remaining metal. Structures of lines down to 50 nm and dots with a diameter of sub 20 nm are presented.
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