| 1. |
-
Abstract Book of the 30th Workshop on Compound Semiconductor Devices and Integrated Circuits in Europe
- 2006
-
Editorial collection (peer-reviewed)abstract
- The organisers and hosts warmly welcome you to the 30th Workshop on Compound Semiconductor Devices and Integrated Circuits in Europe, WOCSDICE 2006, at the Gullmarsstrand Hotel & Conferences in Fiskebäckskil, Sweden, May 14-17, 2006. The symposium is organised by the Chalmers Department of Microtechnology and Nanoscience (MC2) with the aim to create a forum where researchers can discuss latest results and trends in the field of compound semiconductor technology and related science. Established in 1973, WOCSDICE has a long-standing tradition. This workshop brings together both internationally recognised researchers and promising young scientists and engineers to disseminate state-of-the-art research findings in the areas of compound semiconductor materials, associated devices and integrated circuits. This year we have 56 papers (8 invited) divided into nine sessions and more than 78 delegates from 20 countries.Fiskebäckskil is a small restful community situated by Gullmarsfjorden opposite to the village Lysekil. Gullmarsfjorden is Sweden's only true threshold fjord, 25 km deep and 1 to 3 km broad. In the 19th century the small fishing village was transformed into a shipping society. The special wood based architecture of this time is well preserved until today. During the 20th century Fiskebäckskil, surrounded by red granite and the salty sea became a prime choice for summer recreation and swimming. The conference hotel (Gullmarsstrand) building is reverentially renovated and modernised to fulfil the highest expectations for a successful workshop.The workshop is sponsored by the Swedish Research Council (VR), the IEEE Sweden Section, the Swedish Foundation for Strategic Research (SSF-HSEP), Swedish Governmental Agency for Innovation Systems (VINNOVA), OXFORD Plasma Technology and Agilent technologies. We would like to thank these organisations for their support. We would also like to thank everyone who helped to arrange WOCSDICE 2006: the international steering committee for advice; the local organising committee; Eva Hellberg and Peter Jönsson for all WEB support; Catharina Forssén, and Ingrid Collin for help with registrations and payments; the session chairs; and everyone who attends or contributes with a presentation.On behalf of the local organisation committee, we would like to welcome all of you and wish you a pleasant and fruitful stay in Fiskebäckskil.Welcome!Jan Stake and Jan GrahnWOCSDICE2006 Chairmen
|
|
| 2. |
- Ahlberg Gagnér, Viktor, 1989, et al.
(author)
-
Clustering of atomic displacement parameters in bovine trypsin reveals a distributed lattice of atoms with shared chemical properties
- 2019
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 9:1
-
Journal article (peer-reviewed)abstract
- Low-frequency vibrations are crucial for protein structure and function, but only a few experimental techniques can shine light on them. The main challenge when addressing protein dynamics in the terahertz domain is the ubiquitous water that exhibit strong absorption. In this paper, we observe the protein atoms directly using X-ray crystallography in bovine trypsin at 100 K while irradiating the crystals with 0.5 THz radiation alternating on and off states. We observed that the anisotropy of atomic displacements increased upon terahertz irradiation. Atomic displacement similarities developed between chemically related atoms and between atoms of the catalytic machinery. This pattern likely arises from delocalized polar vibrational modes rather than delocalized elastic deformations or rigid-body displacements. The displacement correlation between these atoms were detected by a hierarchical clustering method, which can assist the analysis of other ultra-high resolution crystal structures. These experimental and analytical tools provide a detailed description of protein dynamics to complement the structural information from static diffraction experiments. © 2019, The Author(s).
|
|
| 3. |
- Alderman, Byron, et al.
(author)
-
A New Pillar Geometry for Heterostructure Barrier Varactor Diodes
- 2001
-
In: 12th International Symposium on Space Terahertz Technology. ; , s. 330-339
-
Conference paper (peer-reviewed)abstract
- We report on a novel diode geometry, with reduced thermal resistance, for Heterostructure Barrier Varactor, HBV, diodes. The pillar geometry presented here involves the complete removal of the substrate, electrical contacted is made by the forward and reverse side processing of metallic pillars. We propose that there is a limit to the maximum number of barriers that can be used to increase the power capability of a HBV. An analytical model has been developed to study these effects. In considering the case of a perfect thermal heat sink the limit is found to be fourteen, in applying this model to the new pillar structure this is reduced to six.
|
|
| 4. |
- Amirmazlaghani, Mina, 1984, et al.
(author)
-
Graphene-Si Schottky IR Detector
- 2013
-
In: IEEE Journal of Quantum Electronics. - 0018-9197 .- 1558-1713. ; 49:7, s. 589-594
-
Journal article (peer-reviewed)abstract
- This paper reports on photodetection properties of graphene-Si schottky junction by measuring current-voltage characteristics under 1.55µm excitation laser. The measurements have been done on a junction fabricated by depositing mechanically exfoliated natural graphite on top of the pre-patterned silicon substrate. The electrical Schottky barrier height is estimated to be (0.44-0.47) eV with a minimum responsivity of 2.8mA/W corresponding to an internal quantum efficiency of 10% which is almost an order of magnitude larger than regular Schottky junctions. A possible explanation for the large quantum efficiency related to the 2-D nature of graphene is discussed. Large quantum efficiency, room temperature IR detection, ease of fabrication along with compatibility with Si devices can open a doorway for novel graphene-based photodetectors.
|
|
| 5. |
- Anderberg, Martin, 1992, et al.
(author)
-
A 183-GHz Schottky diode receiver with 4 dB noise figure
- 2019
-
In: IEEE MTT-S International Microwave Symposium Digest. - : IEEE. - 0149-645X. ; 2019-June, s. 172-175
-
Conference paper (peer-reviewed)abstract
- Atmospheric science based on space-borne millimeter wave measurements require reliable and state-of-the art receivers. In particular, the water vapor line at 183.3 GHz motivates the development of sensitive mixers at this frequency. Traditional assembly techniques employed in the production of Schottky diode receivers involve flip-chip mounting and soldering of discrete dies, which prohibit the implementation of reliable and repeatable production processes. In this work, we present a subharmonic 183 GHz mixer implementing a repeatable assembly method using beamlead Schottky diodes. The mixer was integrated with a InP HEMT MMIC low noise intermediate frequency amplifier resulting in a record-low receiver noise temperature of 450 K at 1 mW of local oscillator power measured at room-temperature. The measured Allan time was 10 s and the third order local oscillator spurious power was less than -60 dBm. The proposed assembly method is of particular importance for space-borne missions but also applicable to a wide range of terahertz applications.
|
|
| 6. |
- ANDERSSON, MICHAEL, 1988, et al.
(author)
-
10 dB small-signal graphene FET amplifier
- 2012
-
In: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 48:14, s. 861-863
-
Journal article (peer-reviewed)abstract
- Reported is the realisation of a graphene FET microwave amplifier operating at 1 GHz, exhibiting a small-signal power gain of 10 dB and a noise figure of 6.4 dB. The amplifier utilises a matching inductor on the gate yielding a return loss of 20 dB. The design is optimised for maximum gain and the optimum noise figure is extracted by noise modelling and predicted to be close to 1 dB for the intrinsic graphene FET at this frequency. The presented results complement existing graphene FET applications and are promising for future graphene microwave circuits.
|
|
| 7. |
- ANDERSSON, MICHAEL, 1988, et al.
(author)
-
A 185-215-GHz Subharmonic Resistive Graphene FET Integrated Mixer on Silicon
- 2017
-
In: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 65:1, s. 165-172
-
Journal article (peer-reviewed)abstract
- A 200-GHz integrated resistive subharmonic mixer based on a single chemical vapor deposition graphene field-effect transistor (G-FET) is demonstrated experimentally. This device has a gate length of 0.5 μm and a gate width of 2x40 μm. The G-FET channel is patterned into an array of bow-tie-shaped nanoconstrictions, resulting in the device impedance levels of ~50 Ω and the ON-OFF ratios of ≥4. The integrated mixer circuit is implemented in coplanar waveguide technology and realized on a 100-μm-thick highly resistive silicon substrate. The mixer conversion loss is measured to be 29 ± 2 dB across the 185-210-GHz band with 12.5-11.5 dBm of local oscillator (LO) pump power and >15-dB LO-RF isolation. The estimated 3-dB IF bandwidth is 15 GHz.
|
|
| 8. |
- ANDERSSON, MICHAEL, 1988, et al.
(author)
-
An Accurate Empirical Model Based on Volterra Series for FET Power Detectors
- 2016
-
In: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 64:5, s. 1431-1441
-
Journal article (peer-reviewed)abstract
- An empirical model for field-effect transistor (FET) based power detectors is presented. The electrical model constitutes a Volterra analysis based on a Taylor series expansion of the drain current together with a linear embedding small-signal circuit. It is fully extracted from S-parameters and IV curves. The final result are closed-form expressions for the frequency dependence of the noise equivalent power (NEP) in terms of the FET intrinsic capacitances and parasitic resistances. Excellent model agreement to measured NEP of coplanar access graphene FETs with varying channel dimensions up to 67 GHz is obtained. The influence of gate length on responsivity and NEP is theoretically and experimentally studied.
|
|
| 9. |
- ANDERSSON, MICHAEL, 1988, et al.
(author)
-
Comparison of carrier scattering mechanisms in chemical vapor deposited graphene on fused silica and strontium titanite substrates
- 2014
-
In: Graphene Week 2014.
-
Conference paper (peer-reviewed)abstract
- Graphene is explored for numerous applications for both electronics and photonics. These range from high frequency and low noise field effect transistors to conductive and highly transparent LED electrodes. To exploit the full potential of graphene, the remarkable intrinsic carrier transport properties and tunable, potentially low sheet resistance must be efficiently utilized. However, graphene carrier mobility is currently strongly degraded by extrinsic factors arising mainly from the dielectric environment, i.e. substrate and gate oxide. A proposed route to enhance transport is the use of a high-κ substrate to screen charged impurities at the graphene-substrate interface. In this paper, mobility and carrier concentration in CVD grown graphene films on fused silica (FS, κ=3.9) and strontium titanite (STO, κ=300) substrates are extracted from microwave measurements and compared to Hall data. To model the mobilities scattering by charged impurities (CI), substrate polar phonons (SPP) and resonant centers (RS) are included. Resonant scatterers dominates on strontium titanite and together with charged impurities on fused silica. While resonant scatterers are likely reduced by moving from wet to dry graphene transfer methods, the nominal mobility improvement by screening of charged impurities on high- κ strontium titanite would be masked at room temperature by increased surface phonon scattering.
|
|
| 10. |
- ANDERSSON, MICHAEL, 1988, et al.
(author)
-
Extraction of carrier transport properties in graphene from microwave measurements
- 2014
-
In: European Microwave Conference (EuMC), 2014 44th. ; , s. 359 - 362
-
Conference paper (peer-reviewed)abstract
- Carrier transport parameters of graphene grown by chemical vapor deposition (CVD) and graphene-metal contacts are extracted from microwave measurements in the frequency range 0.1–20 GHz using Corbino disks. It is shown that the charged impurities are effectively screened by the high permittivity of the SrTiO3 substrate. In the case of fused silica substrate the charged impurities are not completely screened and the mobility is limited either by the charged impurities or/and resonant scatterers depending on their relative concentration.
|
|
