| 1. |
- Johansson, Karl-Axel, et al.
(författare)
-
The quality assurance process for the ARTSCAN head and neck study - a practical interactive approach for QA in 3DCRT and IMRT.
- 2008
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Ingår i: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 87:2, s. 290-9
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Tidskriftsartikel (refereegranskat)abstract
- AIM: This paper describes the quality assurance (QA) work performed in the Swedish multicenter ARTSCAN (Accelerated RadioTherapy of Squamous cell CArcinomas in the head and Neck) trial to guarantee high quality in a multicenter study which involved modern radiotherapy such as 3DCRT or IMRT. MATERIALS AND METHODS: The study was closed in June 2006 with 750 randomised patients. Radiation therapy-related data for every patient were sent by each participating centre to the QA office where all trial data were reviewed, analysed and stored. In case of any deviation from the protocol, an interactive process was started between the QA office and the local responsible clinician and/or physicist to increase the compliance to the protocol for future randomised patients. Meetings and workshops were held on a regular basis for discussions on various trial-related issues and for the QA office to report on updated results. RESULTS AND DISCUSSION: This review covers the 734 patients out of a total of 750 who had entered the study. Deviations early in the study were corrected so that the overall compliance to the protocol was very high. There were only negligible variations in doses and dose distributions to target volumes for each specific site and stage. The quality of the treatments was high. Furthermore, an extensive database of treatment parameters was accumulated for future dose-volume vs. endpoint evaluations. CONCLUSIONS: This comprehensive QA programme increased the probability to draw firm conclusions from our study and may serve as a concept for QA work in future radiotherapy trials where comparatively small effects are searched for in a heterogeneous tumour population.
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| 2. |
- Moberg, Christina, et al.
(författare)
-
De unga gör helt rätt när de stämmer staten
- 2022
-
Ingår i: Aftonbladet. - 1103-9000.
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
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| 3. |
- Persson, Anton E.O., et al.
(författare)
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Reduced annealing temperature for ferroelectric HZO on InAs with enhanced polarization
- 2020
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 116:6
-
Tidskriftsartikel (refereegranskat)abstract
- Deposition, annealing, and integration of ferroelectric Hf x Zr 1 - x O 2 (HZO) thin films on the high-mobility semiconductor InAs using atomic layer deposition are investigated. Electrical characterization reveals that the HZO films on InAs exhibit an enhanced remanent polarization compared to films formed on a reference TiN substrate, exceeding 20 μ C / cm 2 even down to an annealing temperature of 370 °C. For device applications, the thermal processes required to form the ferroelectric HZO phase must not degrade the high-κ/InAs interface. We find by evaluation of the capacitance-voltage characteristics that the electrical properties of the high-κ/InAs are not significantly degraded by the annealing process, and high-resolution transmission electron microscopy verifies a maintained sharp high-κ/InAs interface.
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| 4. |
- Söderberg, Stefan, et al.
(författare)
-
MEASURES OF WAIST AND HIP MODIFY SEX-SPECIFIC ASSOCIATIONS BETWEEN BODY MASS INDEX AND PREVALENCE OF CORONARY ARTERY CALCIFICATION IN OPPOSITE DIRECTIONS
- 2019
-
Ingår i: Journal of the American College of Cardiology. - : ELSEVIER SCIENCE INC. - 0735-1097 .- 1558-3597. ; 73:9, s. 13-13
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Obesity is associated with increased risk of cardiovascular disease. However, there is still a debate whether accumulation of fat in certain depots modifies this risk. Using data from the CArdioPulmonary bioImage Study (SCAPIS), we investigated if anthropometric measurements of obesity (waist and hip) modifies the risk of coronary artery calcification. Methods: In the first 15,810 participants in SCAPIS (mean age 58 years, 52% women), data on coronary artery calcification score (CACS) and anthropometry were recorded and traditional cardiovascular risk factors were measured. Body mass index (BMI) was categorized as; <25, 25-30, 30-35 and >35 kg/m2 , quartiles of waist and hip circumferences were constructed within each BMI category and compared using the lowest quartile as reference. Results were adjusted for site, age, smoking and diabetes status. Results: Obesity (BMI >30 kg/m2 ) was found in 21.9% of men and in 20.5% of women. In both sexes the odds ratio (OR) for CACS >0 increased with increasing BMI categories: comparing <25 and >35 kg/m2 , OR = 2.1 (95% CI: 1.6-2.7) for men and OR = 1.4 (1.2-1.8) for women. In addition, increasing quartiles of waist significantly increased the prevalence of CACS >0 for men [p = 0.05; OR = 1.2 (1.0-1.4) for highest quartile] and women [p = 0.005; OR = 1.3 (1.1-1.5)] while increasing quartiles of hip significantly decreased the prevalence for men [p = 0.005; OR = 0.8 (0.6-0.9)] and women [p = 0.04; OR = 0.8 (0.7-0.9)]. Data on education level and physical activity did not affect the model. Conclusion: Increased BMI is associated with increased prevalence of coronary artery calcification and the distribution of fat modifies this risk. Our results suggest that gluteofemoral adipose tissue (hip) counteracts the negative effects associated with BMI and abdominal adipose tissue (waist).
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| 5. |
- Adolfsson, Karl, et al.
(författare)
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Fluorescent Nanowire Heterostructures as a Versatile Tool for Biology Applications
- 2013
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 13:10, s. 4728-4732
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Tidskriftsartikel (refereegranskat)abstract
- Nanowires are increasingly used in biology, as sensors, as injection devices, and us model systems for toxicity studies. Currently, in situ visualization of nanowires in biological media is done using organic dyes, which a;:e prone to photobleaching, or using microscopy methods which either yield poor resolution or require a sophisticated setup. Here we show that inherently fluorescent nanowire axial heterostructnies c:an be used to localize and identify nanowires in cells and tissue; By synthesizing GaP GaInP nanowire heterostructures, with nonfluorescent GaP segments and fluorescent GaInP segments, we created a barcode labeling system enabling the distinction of the nanowire morphological and chemical properties using fluorescence microscopy. The GaInP photoluminescence stability, combined with the fact that the nanowires can be coated with different materials while retaining their fluorescence, make these nanowires promising tools for biological and nanotoxicological studies.
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| 6. |
- Berg, Martin, et al.
(författare)
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Electrical Characterization and Modeling of Gate-Last Vertical InAs Nanowire MOSFETs on Si
- 2016
-
Ingår i: IEEE Electron Device Letters. - 0741-3106. ; 37:8, s. 966-969
-
Tidskriftsartikel (refereegranskat)abstract
- Vertical InAs nanowire transistors are fabricated on Si using a gate-last method, allowing for lithography-based control of the vertical gate length. The best devices combine good ON- and OFF-performance, exhibiting an ON-current of 0.14 mA/μm, and a sub-threshold swing of 90 mV/dec at 190 nm LG. The device with the highest transconductance shows a peak value of 1.6 mS/μm. From RF measurements, the border trap densities are calculated and compared between devices fabricated using the gate-last and gate-first approaches, demonstrating no significant difference in trap densities. The results thus confirm the usefulness of implementing digital etching in thinning down the channel dimensions.
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| 7. |
- Berg, Martin, et al.
(författare)
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InAs nanowire MOSFETs in three-transistor configurations: single balanced RF down-conversion mixers.
- 2014
-
Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 25:48
-
Tidskriftsartikel (refereegranskat)abstract
- Integration of III-V semiconductors on Si substrates allows for the realization of high-performance, low power III-V electronics on the Si-platform. In this work, we demonstrate the implementation of single balanced down-conversion mixer circuits, fabricated using vertically aligned InAs nanowire devices on Si. A thin, highly doped InAs buffer layer has been introduced to reduce the access resistance and serve as a bottom electrode. Low-frequency voltage conversion gain is measured up to 7 dB for a supply voltage of 1.5V. Operation of these mixers extends into the GHz regime with a [Formula: see text] cut-off frequency of 2 GHz, limited by the optical lithography system used. The circuit dc power consumption is measured at 3.9 mW.
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| 8. |
- Berg, Martin, et al.
(författare)
-
Self-aligned, gate-last process for vertical InAs nanowire MOSFETs on Si
- 2016
-
Ingår i: Technical Digest - International Electron Devices Meeting, IEDM. - 9781467398930 ; 2016-February
-
Konferensbidrag (refereegranskat)abstract
- In this work, we present a novel self-aligned gate-last fabrication process for vertical nanowire metal-oxide-semiconductor field-effect transistors. The fabrication method allows for exposure dose-defined gate lengths and a local diameter reduction of the intrinsic channel segment, while maintaining thicker highly doped access regions. Using this process, InAs nanowire transistors combining good on-and off-performance are fabricated demonstrating Q = gm,max/SS = 8.2, which is higher than any previously reported vertical nanowire MOSFET.
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| 9. |
- Berg, Martin, et al.
(författare)
-
Single Balanced Down-Conversion Mixer Utilizing Indium Arsenide Nanowire MOSFETs
- 2014
-
Ingår i: 26th International Conference on Indium Phosphideand Related Materials (IPRM). - 1092-8669.
-
Konferensbidrag (refereegranskat)abstract
- We have fabricated single balanced down-conversion mixer circuits using InAs nanowire MOSFETs as both active and passive devices. This is achieved by a combination of electron beam lithography and UV-lithography with a line width of 12 mu m. The circuits exhibit a low frequency voltage conversion gain of 6 dB, a -3 dB cutoff frequency of 2 GHz and a power consumption of 3.8 mW, while operating at a supply voltage of 1.5 V. The circuits retain circuit functionality even for a supply voltage of 1 V.
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| 10. |
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| 11. |
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| 12. |
- Egard, Mikael, et al.
(författare)
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High-Frequency Performance of Self-Aligned Gate-Last Surface Channel In0.53Ga0.47As MOSFET
- 2012
-
Ingår i: IEEE Electron Device Letters. - 0741-3106. ; 33:3, s. 369-371
-
Tidskriftsartikel (refereegranskat)abstract
- We have developed a self-aligned L-g = 55 nm In-0.53 Ga-0.47 As MOSFET incorporating metal-organic chemical vapor deposition regrown n(++) In0.6Ga0.4As source and drain regions, which enables a record low on-resistance of 199 Omega mu m. The regrowth process includes an InP support layer, which is later removed selectively to the n(++) contact layer. This process forms a high-frequency compatible device using a low-complexity fabrication scheme. We report on high-frequency measurements showing f(max) of 292 GHz and f(t) of 244 GHz. These results are accompanied by modeling of the device, which accounts for the frequency response of gate oxide border traps and impact ionization phenomenon found in narrow band gap FETs. The device also shows a high drive current of 2.0 mA/mu m and a high extrinsic transconductance of 1.9 mS/mu m. These excellent properties are attributed to the use of a gate-last process, which does not include high temperature or dry-etch processes.
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| 13. |
- Egard, Mikael, et al.
(författare)
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Vertical InAs nanowire wrap gate transistors with f(t) > 7 GHz and f(max) > 20 GHz.
- 2010
-
Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 10:3, s. 809-812
-
Tidskriftsartikel (refereegranskat)abstract
- In this letter we report on high-frequency measurements on vertically standing III-V nanowire wrap-gate MOSFETs (metal-oxide-semiconductor field-effect transistors). The nanowire transistors are fabricated from InAs nanowires that are epitaxially grown on a semi-insulating InP substrate. All three terminals of the MOSFETs are defined by wrap around contacts. This makes it possible to perform high-frequency measurements on the vertical InAs MOSFETs. We present S-parameter measurements performed on a matrix consisting of 70 InAs nanowire MOSFETs, which have a gate length of about 100 nm. The highest unity current gain cutoff frequency, f(t), extracted from these measurements is 7.4 GHz and the maximum frequency of oscillation, f(max), is higher than 20 GHz. This demonstrates that this is a viable technique for fabricating high-frequency integrated circuits consisting of vertical nanowires.
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| 14. |
- Gomez-Carretero, Salvador, et al.
(författare)
-
Salmonella Biofilm Modulation with Electrically Conducting Polymers
- 2014
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Biofilms are ubiquitous in many human activities, constituting a threat or an advantage depending on the context of application. It is therefore of great interest to obtain new materials to study and control how biofilms are formed. Here, heparin and DBS (dodecylbenzenesulfonate) are incorporated as counter-ions to the PEDOT (poly(3,4-ethylenedioxythiophene)) backbone, forming conducting polymer thin-films. Polymer synthesis is based on electrodeposition, allowing for the adjustment, during fabrication, of properties like charge and hydrophobicity, important in bacterial adhesion. The electrochemical redox state of the polymer is of fundamental importance in Salmonella enterica Serovar Typhimurium biofilm modulation. Oxidized composites show increased levels of biofilm growth compared to reduced and pristine polymer films. As a result, biofilm formation is modulated by the application of a low electric voltage. Moreover, biofilm morphology and topology are affected by both the electrochemical redox state and the incorporated counter-ion, making these materials a useful tool in biofilm engineering.
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| 15. |
- Gunnarsson, Frida, et al.
(författare)
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Comagotchi - a social toy
- 2001
-
Ingår i: Reprints from the PCC Summer School.
-
Konferensbidrag (refereegranskat)
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| 16. |
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| 17. |
- Kurdve, Martin, Dr, 1971-, et al.
(författare)
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Lead-Time Effect Comparison of Additive Manufacturing with Conventional Alternatives
- 2020
-
Ingår i: Advances in Transdisciplinary Engineering at SPS2020. - : IOS Press BV. - 9781614994398 ; 13, s. 672-679
-
Konferensbidrag (refereegranskat)abstract
- This single case study used value stream mapping as input data to analyse alternatives for production of quenching tools in an on-site tool department of an automotive manufacturer. The existing manufacturing organised as a functional workshop was compared to the alternatives, adding an additive manufacturing cell or a conventional automated cell, with regards to lead-Time and needed process changes. The results indicate that lead-Time savings should not be the only reason for considering additive manufacturing. When it is beneficial for design and product functionality improvements, however, lead time improvements may give a contribution to the business case. © 2020 The authors
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| 18. |
- Li, Zhen, et al.
(författare)
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Cellular traction forces : a useful parameter in cancer research
- 2017
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3372 .- 2040-3364. ; 9:48, s. 19039-19044
-
Tidskriftsartikel (refereegranskat)abstract
- The search for new cancer biomarkers is essential for fundamental research, diagnostics, as well as for patient treatment and monitoring. Whereas most cancer biomarkers are biomolecules, an increasing number of studies show that mechanical cues are promising biomarker candidates. Although cell deformability has been shown to be a possible cancer biomarker, cellular forces as cancer biomarkers have been left largely unexplored. Here, we measure traction forces of cancer and normal-like cells at high spatial resolution using a robust method based on dense vertical arrays of nanowires. A force map is created using automated image analysis based on the localization of the fluorescent tips of the nanowires. We show that the force distribution and magnitude differ between MCF7 breast cancer cells and MCF10A normal-like breast epithelial cells, and that monitoring traction forces can be used to investigate the effects of anticancer drugs.
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| 19. |
- Lind, Erik, et al.
(författare)
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High Frequency Performance of Vertical InAs Nanowire MOSFET
- 2010
-
Ingår i: 2010 22Nd International Conference On Indium Phosphide And Related Materials (Iprm). - 1092-8669. - 9781424459193
-
Konferensbidrag (refereegranskat)abstract
- We report on RF characterization of vertical, 100-nm-gate length InAs nanowire MOSFETs, utilizing wrap-gate technology and Al2O3 high-kappa gate oxide. The transistors show f(t)=5.6 GHz and f(max)=22 GHz, mainly limited by parasitic capacitances. The RF device performance is described using a hybrid-pi model taking hole generation at the drain into account. Electrostatic modeling of the parasitic capacitances for arrays of vertical nanowires indicates that a strong reduction in extrinsic capacitances can be achieved for devices with a small inter-wire separation.
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| 20. |
- Lind, Johanna, et al.
(författare)
-
Reduced functional brain activity response in cognitively intact apolipoprotein E ε4 carriers
- 2006
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Ingår i: Brain. - : Oxford University Press. - 0006-8950 .- 1460-2156. ; 129:5, s. 1240-1248
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Tidskriftsartikel (refereegranskat)abstract
- The apolipoprotein E epsilon4 (APOE epsilon4) is the main known genetic risk factor for Alzheimer's disease. Genetic assessments in combination with other diagnostic tools, such as neuroimaging, have the potential to facilitate early diagnosis. In this large-scale functional MRI (fMRI) study, we have contrasted 30 APOE epsilon4 carriers (age range: 49-74 years; 19 females), of which 10 were homozygous for the epsilon4 allele, and 30 non-carriers with regard to brain activity during a semantic categorization task. Test groups were closely matched for sex, age and education. Critically, both groups were cognitively intact and thus symptom-free of Alzheimer's disease. APOE epsilon4 carriers showed reduced task-related responses in the left inferior parietal cortex, and bilaterally in the anterior cingulate region. A dose-related response was observed in the parietal area such that diminution was most pronounced in homozygous compared with heterozygous carriers. In addition, contrasts of processing novel versus familiar items revealed an abnormal response in the right hippocampus in the APOE epsilon4 group, mainly expressed as diminished sensitivity to the relative novelty of stimuli. Collectively, these findings indicate that genetic risk translates into reduced functional brain activity, in regions pertinent to Alzheimer's disease, well before alterations can be detected at the behavioural level.
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| 21. |
- Mamidala, Saketh, Ram, et al.
(författare)
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A 4F2 Vertical Gate-all-around Nanowire Compute-in-memory Device Integrated in (1T1R) Cross-Point Arrays on Silicon
- 2022
-
Ingår i: IEEE Silicon Nanoelectronics Workshop (SNW). - 9781665459792 ; , s. 1-2
-
Konferensbidrag (refereegranskat)abstract
- Complete 4F2 vertical nanowire (VNW) 1T1R cells with 106 cycles switching endurance and with a demonstrated capability of performing Boolean logic are fabricated and characterized in cross-point arrays. The performance of the vertical 1T1R cell is benefited from using the same III-V/high- k interface both for the vertical GAA MOSFET selector as well as the ReRAM. In this paper, we also compare the InAs nanowire implementation to a nanowire with an InGaAs top segment to utilize the relatively larger bandgap of InGaAs to reduce sneak-path leakage currents.
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| 22. |
- Mamidala, Saketh, Ram, et al.
(författare)
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Controlling Filament Stability in Scaled Oxides (3 nm) for High Endurance (>106) Low Voltage ITO/HfO2 RRAMs for Future 3D Integration
- 2021
-
Ingår i: 2021 Device Research Conference (DRC). - 9781665412407 - 9781665429580
-
Konferensbidrag (refereegranskat)abstract
- Non-volatile resistive-random-access-memories (RRAMs), which are highly scalable, cost-efficient and fast, are needed to meet the future computational needs beyond the traditional von-Neumann architecture. Oxygen vacancy RRAMs in particular have been demonstrated to operate at nanosecond programming ranges with low voltages as well as being integrated in dense cross-point arrays [1] . ITO/HfO 2 based RRAMs have emerged as a promising material stack due to its ultra-low switching voltages, self-compliance properties and the transparency of ITO that extends the material stack’s applications into display/wearable electronics [2] . As the different RRAM technologies are reaching maturity, scaling down the oxide thicknesses is now becoming vital for compatibility with dense 3D integration as projected by the IRDS 2020 [3] . We report that, when operated at relevant current levels (sub 100 µA), the filament integrity of ITO/HfO2 RRAM with a thin high-k oxide (3 nm) can be controlled depending on the deposition conditions, where a thermal ALD (TALD) process results in a stable filament formation as compared to a plasma enhanced ALD (PEALD) process used for depositing HfO2 . Our results further indicate that the RRAM RESET is more gradual for the TALD (oxygen deficient) HfO2 as compared to the abrupt switching behavior for the PEALD (oxygen rich) HfO2 .
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| 23. |
- Mamidala, Saketh, Ram, et al.
(författare)
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High-density logic-in-memory devices using vertical indium arsenide nanowires on silicon
- 2021
-
Ingår i: Nature Electronics. - : Springer Science and Business Media LLC. - 2520-1131. ; , s. 914-914
-
Tidskriftsartikel (refereegranskat)abstract
- In-memory computing can be used to overcome the von Neumann bottleneck—the need to shuffle data between separate memory and computational units—and help improve computing performance. Co-integrated vertical transistor selectors (1T) and resistive memory elements (1R) in a 1T1R configuration offer advantages of scalability, speed and energy efficiency in current mass storage applications, and such 1T1R cells could also be potentially used for in-memory computation architectures. Here we show that a vertical transistor and resistive memory can be integrated onto a single vertical indium arsenide nanowire on silicon. The approach relies on an interface between the III–V semiconductor nanowire and a high-κ dielectric (hafnium oxide), which provides an oxide layer that can operate either as a vertical transistor selector or a high-performance resistive memory. The resulting 1T1R cells allow Boolean logic operations to be implemented in a single vertical nanowire with a minimal area footprint
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| 24. |
- Mamidala, Saketh, Ram, et al.
(författare)
-
Low-Power Resistive Memory Integrated on III-V Vertical Nanowire MOSFETs on Silicon
- 2020
-
Ingår i: IEEE Electron Device Letters. - 0741-3106. ; 41:9, s. 1432-1435
-
Tidskriftsartikel (refereegranskat)abstract
- III-V vertical nanowire MOSFETs (VNW-FETs) have the potential to extend Moore’s law owing to their excellent material properties. To integrate highly scaled memory cells coupled with high performance selectors at minimal memory cell area, it is attractive to integrate low-power resistive random access memory (RRAM) cells directly on to III-V VNW-FETs. In this work, we report the experimental demonstration of successful RRAM integration with III-V VNW-FETs. The combined use of VNW-FET drain metal electrode and the RRAM bottom electrode reduces the process complexity and maintains material compatibility. The vertical nanowire geometry allows the RRAM cell area to be aggressively scaled down to 0.01 μm2 enabling realization of dense memory (1T1R) cross-point arrays on silicon.
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| 25. |
- Moubah, Reda, et al.
(författare)
-
Discrete Layer-by-Layer Magnetic Switching in Fe/MgO(001) Superlattices
- 2016
-
Ingår i: Physical Review Applied. - : American physical society. - 2331-7019. ; 5:4
-
Tidskriftsartikel (refereegranskat)abstract
- We report on a discrete layer-by-layer magnetic switching in Fe/MgO superlattices driven by an antiferromagnetic interlayer exchange coupling. The strong interlayer coupling is mediated by tunneling through MgO layers with thicknesses up to at least 1.8 nm, and the coupling strength varies with MgO thickness. Furthermore, the competition between the interlayer coupling and magnetocrystalline anisotropy stabilizes both 90 degrees and 180 degrees periodic alignment of adjacent layers throughout the entire superlattice. The tunable layer-by-layer switching, coupled with the giant tunneling magnetoresistance of Fe/MgO/Fe junctions, is an appealing combination for three-dimensional spintronic memories and logic devices.
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| 26. |
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| 27. |
- Olsson, Karl-Gunnar, 1955, et al.
(författare)
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Architecture and Engineering - education of Form and Force
- 2019
-
Ingår i: IASS Symposium 2019 - 60th Anniversary Symposium of the International Association for Shell and Spatial Structures; Structural Membranes 2019 - 9th International Conference on Textile Composites and Inflatable Structures, FORM and FORCE. - 9788412110104 ; , s. 145-152
-
Konferensbidrag (refereegranskat)abstract
- Inspired by the work and attitudes of architects and engineers like Jorg Schlaich, Renzo Piano, Piero Luigi Nervi, Sverre Fehn, Ted Happold, and environments like ILEK in Stuttgart and ETH in Zurich, a vision of a new kind of architects and engineers arose at Chalmers University of Technology in the early 2000. With support from the university and the branch, a double degree Architecture and Engineering programme was developed. Since the programme started in 2006 it has been a very popular programme, and among all Swedish MSc in Engineering and Master of Architecture programmes it has almost every year been the most difficult programme to get admitted to. The concept of the programme is a 180 ects (European Credit Transfer and Accumulation System) bachelor's degree, where the fundamentals from the engineering science: mathematics, mechanics, physics and materials, is combined with history of architecture and engineering, artistic explorative courses, and the fundamentals of the architectural design process. After three years the students can choose to continue for a Master of Science in Engineering with different possible directions, from mathematics and data science to industrial ecology, acoustics, management, structural engineering, and building technology, or to continue for a Master of Architecture. For the latter they need 150 etcs minimum in pure architectural design projects. In this paper the basic concepts of the programme, the culture developed around it and the strengths we can experience in the examined students will be discussed and reflected. Today students from the programme can be found at architecture and engineering companies all over the world and are appreciated for their ability to address complex architectural and engineering design issues with attitudes, insights and skills from the both professions.
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| 28. |
- Persson, Erik Florin, et al.
(författare)
-
Inledning
- 2021
-
Ingår i: Filmens Göteborg: Spår, erfarenheter och resultat från ett samverkande forskningsprojekt. - Göteborg : Riksarkivet. - 9789198465792 ; , s. 7-10
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Samskriven inledning om forskningsprojektets och bokens tillkomsthistoria och arbetsprocess.
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| 29. |
- Persson, Karl-Magnus, et al.
(författare)
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1/f-noise in Vertical InAs Nanowire Transistors
- 2013
-
Ingår i: 2013 International Conference on Indium Phosphide and Related Materials (IPRM). - 1092-8669. ; , s. 1-2
-
Konferensbidrag (refereegranskat)abstract
- The material quality at high-k interfaces are a major concern for FET devices. We study the effect on two types of InAs nanowire (NW) transistors and compare their characteristics. It is found that by introducing an inner layer of Al2O3 at the high-kappa interface, the low frequency noise (LFN) performance regarding gate voltage noise spectral density, S-Vg, is improved by one order of magnitude per unit gate area.
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| 30. |
- Persson, Karl-Magnus, et al.
(författare)
-
Cross-Point Arrays with Low-Power ITO-HfO2 Resistive Memory Cells Integrated on Vertical III-V Nanowires
- 2020
-
Ingår i: Advanced Electronic Materials. - : Wiley. - 2199-160X. ; 6:6
-
Tidskriftsartikel (refereegranskat)abstract
- Vertical nanowires with cointegrated metal-oxide-semiconductor field-effect-transistor (MOSFET) selectors and nonvolatile resistive random access memory (RRAM) cells represent a promising candidate for fast, energy-efficient, cross-point memory cells. This paper explores indium-tin-oxide-hafnium-dioxide RRAM cells integrated onto arrays of indium-arsenide (InAs) vertical nanowires with a resulting area of 0.06 µm2 per cell. For low current operation, an improved switching uniformity over the intrinsic self-compliant behavior is demonstrated when using an external InAs nanowire MOSFET selector in series. The memory cells show consistent switching voltages below ±1 V and a switching cycle endurance of 106 is demonstrated. The developed fabrication scheme is fully compatible with low-ON-resistance vertical III-V nanowire MOSFET selectors, where operational compatibility with the initial high-field filament forming is established. Due to the small footprint of a vertical implementation, high density integration is achievable, and with a measured programming energy for 50 ns pulses at 0.49 pJ, the technology promises fast and ultralow power cross-point memory arrays.
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| 31. |
- Persson, Kristin M, et al.
(författare)
-
Electronic control of cell detachment using a self-doped conducting polymer
- 2011
-
Ingår i: Advanced Materials. - : Wiley-Blackwell. - 0935-9648 .- 1521-4095. ; 23:38, s. 4403-4408
-
Tidskriftsartikel (refereegranskat)abstract
- An electronic detachment technology based on thin films of a poly(3,4-ethylene-dioxythiophene) derivative is evaluated for controlled release of human epithelial cells. When applying a potential of 1 V, the redox-responsive polymer films detach and disintegrate and at the same time release cells cultured on top in the absence of any enzymatic treatment with excellent preservation of membrane proteins and cell viability.
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| 32. |
- Persson, Karl-Magnus, et al.
(författare)
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Extrinsic and Intrinsic Performance of Vertical InAs Nanowire MOSFETs on Si Substrates
- 2013
-
Ingår i: IEEE Transactions on Electron Devices. - 0018-9383. ; 60:9, s. 2761-2767
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents DC and RF characterization as well as modeling of vertical InAs nanowire MOSFETs with LG = 200 nm and Al2O3/HfO2 high-κ dielectric. Measurements at VDS = 0.5 V show that high transconductance (gm = 1.37 mS/μm), high drive current (IDS = 1.34 mA/μm), and low on-resistance (RON = 287 Ωμm) can be realized using vertical InAs nanowires on Si substrates. By measuring the 1/f-noise, the gate area normalized gate voltage noise spectral density, SVG·LG·WG, is determined to be lowered one order of magnitude compared to similar devices with a high-κ film consisting of HfO2 only. Additionally, with a virtual source model we are able to determine the intrinsic transport properties. These devices (LG = 200 nm) show a high injection velocity (vinj = 1.7·107 cm/s) with a performance degradation for array FETs predominantly due to an increase in series resistance.
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| 33. |
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| 34. |
- Persson, Karl-Magnus, et al.
(författare)
-
InAs nanowire MOSFET differential active mixer on Si-substrate
- 2014
-
Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 50:9, s. 682-682
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Tidskriftsartikel (refereegranskat)abstract
- An active single balanced down-conversion mixer is implemented using InAs nanowire metal oxide semiconductor field effect transistors (MOSFETs) as both active devices and passive resistive loads. Circuits with 6 dB low-frequency voltage gain and a 3 dB bandwidth of 2 GHz are measured for a DC power consumption of 3.8 mW from a 1.5 V supply. The circuits are fabricated using contacts made with 12 μmline- width optical lithography.
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| 35. |
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| 36. |
- Persson, Karl-magnus, et al.
(författare)
-
Investigation of Reverse Filament Formation in ITO/HfO2-based RRAM
- 2019
-
Ingår i: 2019 Device Research Conference (DRC). - 9781728121123 - 9781728121116 ; , s. 91-92
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- To overcome the large discrepancy in speed between computational devices and that of contemporary large capacity non-volatile memory (NVM) technologies, resistive random access memory (RRAM) technologies are seen as promising candidates, offering speed/energy improvements in several orders of magnitude while being 3D integration compatible [1]. Indium-Tin-Oxide (ITO) has several unique properties for RRAM operation, perhaps most prominently the self-compliance and an ultra-low switching voltage (±200 mV) [2]. We report on considerations for ITO electrical bottom electrode (BE) RRAM where we vary the ALD oxide deposition parameters in order to improve the reverse filament formation (RFF) occurring at large reset voltages. RFF is when the conducting filament is reformed. One of the key parameters of RRAM is the endurance, how many times it can switch before failure. The RFF is one of the limitations in the number of switches until a device reaches failure and it is thus of high importance to ensure a sufficient margin between the highest applied reset voltage and the RFF voltage not to compromise the endurance. We optimized the oxide to improve the RFF properties.
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| 37. |
- Persson, Karl-Magnus, et al.
(författare)
-
Low-frequency noise in vertical InAs nanowire FETs
- 2010
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Ingår i: IEEE Electron Device Letters. - 0741-3106. ; 31:5, s. 428-430
-
Tidskriftsartikel (refereegranskat)abstract
- This letter presents dc characteristics and low-frequency noise (LFN) measurements on single vertical InAs nanowire MOSFETs with 35-nm gate length and HfO2 high-kappa dielectric. The average normalized transconductance for three devices is 0.16 S/mm, with a subthreshold slope of 130 mV/decade. At 10 Hz, the normalized noise power S-I/I-d(2) measures 7.3 x 10(-7) Hz(-1). Moreover, the material-dependent Hooge's parameter at room temperature is estimated to be 4.2 x 10(-3).
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| 38. |
- Persson, Karl-Magnus
(författare)
-
Nanowire Transistors and RF Circuits for Low-Power Applications
- 2014
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The background of this thesis is related to the steadily increasing demand of higher bandwidth and lower power consumption for transmitting data. The work aims at demonstrating how new types of structures, at the nanoscale, combined with what is referred to as exotic materials, can help benefit in electronics by lowering the consumed power, possibly by an order of magnitude, compared to the industry standard, silicon (Si), used today. Nanowires are semiconductor rods, with two dimensions at the nanoscale, which can be either grown with a bottom-up technique, or etched out with a top-down approach. The research interest concerning nanowires has gradually increasing for over two decades. Today, few have doubts that nanowires represent an attractive alternative, as scaling of planar structures has reached fundamental limits. With the enhanced electrostatics of a surrounding gate, nanowires offer the possibility of continued miniaturization, giving semiconductors a prolonged window of performance improvements. As a material choice, compound semiconductors with elements from group III and V (III-Vs), such as indium arsenide (InAs), have the possibility to dramatically decrease power consumption. The reason is the inherent electron transport properties of III-Vs, where an electron can travel, in the order of, 10 times faster than in Si. In the projected future, inclusion of III-Vs, as an extension to the Si-CMOS platform, seems almost inevitable, with many of the largest electronics manufacturing companies showing great interest. To investigate the technology potential, we have fabricated InAs nanowire metal-oxide-semiconductor field effect transistors (NW-FETs). The performance has been evaluated measuring both RF and DC characteristics. The best devices show a transconductance of 1.36 mS/µm (a device with a single nanowire, normalized to the nanowire circumference) and a maximum unilateral power gain at 57 GHz (for a device with several parallel nanowires), both values at a drive voltage of 0.5 V. The performance metrics are found to be limited by the capacitive load of the contact pads as well as the resistance in the non-gated segments of the nanowires. Using computer models, we have also been able to extract intrinsic transport properties, quantifying the velocity of charge carrier injection, which is the limiting property of semi-ballistic and ballistic devices. The value for our 45-nm-in-diameter nanowires, with 200 nm channel length, is determined to 1.7∙107 cm/s, comparable to other state-of-the-art devices at the same channel length. To demonstrate a higher level of functionality, we have connected several NW-FETs in a circuit. The fabricated circuit is a single balanced differential direct conversion mixer and is composed of three stages; transconductance, mixing, and transimpedance. The basic idea of the mixer circuit is that an information signal can either be extracted from or inserted into a carrier wave at a higher frequency than the information wave itself. It is the relative size of the first and the third stage that accounts for the circuit conversion gain. Measured circuits show a voltage conversion gain of 6 dB and a 3-dB bandwidth of 2 GHz. A conversion mixer is a vital component when building a transceiver, like those found in a cellphone and any other type of radio signal transmitting device. For all types of signals, noise imposes a fundamental limitation on the minimal, distinguishable amplitude. As transistors are scaled down, fewer carriers are involved in charge transport, and the impact of frequency dependent low-frequency noise gets relatively larger. Aiming towards low power applications, it is thus of importance to minimize the amount of transistor generated noise. Included in the thesis are studies of the level and origin of low-frequency 1/f-noise generated in NW-FETs. The measured noise spectral density is comparable to other non-planar devices, including those fabricated in Si. The data suggest that the level of generated noise can be substantially lowered by improving the high-k dielectric film quality and the channel interface. One significant discovery is that the part of the noise originating from the bulk nanowire, identified as mobility fluctuations, is comparably much lower than the measured noise level related to the nanowire surface. This result is promising as mobility fluctuations set the lower limit of what is achievable within a material system.
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| 39. |
- Persson, Karl-Magnus, et al.
(författare)
-
Surface and core contribution to 1/f-noise in InAs nanowire metal-oxide-semiconductor field-effect transistors
- 2013
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 103:3
-
Tidskriftsartikel (refereegranskat)abstract
- By measuring 1/f-noise in wrap-gated InAs nanowire metal-oxide-semiconductor field-effect transistors with transport dominating, controllably, in either an inner, core channel, or an outer, surface channel, it is possible to accurately evaluate the material quality related Hooge-parameter, alpha(H), with reduced interference from the surface properties. The devices show low values of alpha(H) similar to 4 x 10(-5). At forward bias, where the data suggest that the 1/f-noise is dominated by the contribution from the high-k interface, devices show low values of normalized noise spectral density. (C) 2013 AIP Publishing LLC.
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| 40. |
- Persson, Karl-Magnus, et al.
(författare)
-
Ultra-Scaled AlOx Diffusion Barriers for Multibit HfOx RRAM Operation
- 2021
-
Ingår i: IEEE Journal of the Electron Devices Society. - 2168-6734. ; 9, s. 564-569
-
Tidskriftsartikel (refereegranskat)abstract
- For dense very large scale integration (VLSI) of high performance, multibit resistive memory (RRAM), scalability of material dimensions, as well as the operational sensitivity of the RRAM to voltage fluctuations, have to be considered. This report presents the benefits of adding 0.5-nm thick AlO x diffusion barriers at the different electrode interfaces of HfO x . It is found that implementing AlO x -layers at both the bottom and the top electrode interface enables a tight control of the oxygen vacancy filament, resulting in low switching voltages and significantly improving switching endurance up to 10 6 cycles using a performance limiting resistor compliance. It is also shown that the filament in its low resistive state ( RLRS ) can be linearly reduced and enlarged at levels compatible to the conduction limitations of scaled selectors using an external 1T1R transistor compliance. With selector controlled resistance modulation, the RLRS becomes independent of the magnitude of the programming voltage and thus less sensitive to losses throughout a large memory array.
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| 41. |
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| 42. |
- Wallentin, Jesper, et al.
(författare)
-
Hard X-ray Detection Using a Single nm Diameter Nanowire
- 2014
-
Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 14:12, s. 7071-7076
-
Tidskriftsartikel (refereegranskat)abstract
- Submicron sized sensors could allow higher resolution in X-ray imaging and diffraction measurements, which are ubiquitous for materials science and medicine. We present electrical measurements of a single 100 nm diameter InP nanowire transistor exposed to hard X-rays. The X-ray induced conductance is over 5 orders of magnitude larger than expected from reported data for X-ray absorption and carrier lifetimes. Time-resolved measurements show very long characteristic lifetimes on the order of seconds, tentatively attributed to long-lived traps, which give a strong amplification effect. As a proof of concept, we use the nanowire to directly image an X-ray nanofocus with submicron resolution.
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| 43. |
- Yong, Zhihua, et al.
(författare)
-
The Effect of Deposition Conditions on Heterointerface-Driven Band Alignment and Resistive Switching Properties
- 2022
-
Ingår i: Advanced Electronic Materials. - : Wiley. - 2199-160X. ; 8:11
-
Tidskriftsartikel (refereegranskat)abstract
- Titanium nitride and hafnium oxide stack have been widely used in various resistive memory elements since the materials are complementary-metal-oxide-semiconductor compatible. The understanding of the interface properties between the electrode and the oxide is important in designing the memory behavior. To bridge this understanding, HfOx grown using plasma enhanced atomic layer deposition (PEALD) and thermal atomic layer deposition (TALD) are compared, in terms of band alignment and electrical performances in the HfOx/PEALD TiN stacks. X-ray photoelectron spectroscopy reveals a thicker interfacial TiO2 layer in the PEALD HfOx/TiN stack whose interface resembles more to the PEALD HfOx/TiO2 interface (conduction band offset ΔEC = 1.63 eV), whereas the TALD HfOx stack interface resembles more to the TALD HfOx/TiN interface (ΔEC = 2.22 eV). The increase in the forming voltage and the early onset of reverse filament formation (RFF) in the I–V measurements for the PEALD HfOx stack confirms the presence of the thicker interfacial layer; the early onset of RFF is likely related to a smaller ΔEC. The findings show the importance of understanding the intricate details of the material stack, where ΔEC difference and the presence of a thicker TiO2 interfacial layer due to different deposition procedures affect the device performance.
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| 44. |
- Yong, Zhihua, et al.
(författare)
-
Tuning oxygen vacancies and resistive switching properties in ultra-thin HfO2 RRAM via TiN bottom electrode and interface engineering
- 2021
-
Ingår i: Applied Surface Science. - : Elsevier BV. - 1873-5584 .- 0169-4332. ; 551
-
Tidskriftsartikel (refereegranskat)abstract
- Resistive random access memory (RRAM) technologies based on non-volatile resistive filament redox switching oxides have the potential of drastically improving the performance of future mass-storage solutions. However, the physico-chemical properties of the TiN bottom metal electrode (BME) can significantly alter the resistive switching (RS) behavior of the oxygen-vacancy RRAM devices, yet the correlation between RS and the physico-chemical properties of TiN and HfOx/TiN interface remains unclear. Here, we establish this particular correlation via detailed material and electrical characterization for the purpose of achieving further performance enhancement of the stack integration. Two types of RRAM stacks were fabricated where the TiN BME was fabricated by physical vapor deposition (PVD) and atomic layer deposition (ALD), respectively. The HfOx layer in HfOx/PVD-TiN is more oxygen deficient than that of the HfOx/ALD-TiN because of more defective PVD-TiN and probably because pristine ALD-TiN has a thicker TiO2 overlayer. Higher concentration of oxygen vacancies induces a larger magnitude of band bending at the HfOx/PVD-TiN interface and leads to the formation of a higher Schottky barrier. Pulsed endurance measurements of up to 106 switches, with 10 μA ± 1.0 V pulses, demonstrate the potential of the studied ultra-thin-HfOx/TiN device stack for dense, large scale, and low-power memory integration.
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| 45. |
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