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- Zetterling, Carl-Mikael, et al.
(författare)
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Challenges for High Temperature Silicon Carbide Electronics
- 2003
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Ingår i: Materials Research Society Symposium - Proceedings. - San Francisco, CA. ; , s. 15-25
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Konferensbidrag (refereegranskat)abstract
- Silicon carbide has been proposed as an excellent material for high-frequency, high-power and high-temperature electronics. High power and high frequency applications have been pursued for quite some time in SiC with a great deal of success in terms of demonstrated devices. However, self-heating problems due to the much higher power densities that result when ten times higher electrical fields are used inside the devices needs to be addressed. High-temperature electronics has not yet experienced as much attention and success, possibly because there is no immediate market. This paper will review some of the advances that have been made in high-temperature electronics using silicon carbide, starting from process technology, continuing with device design, and finishing with circuit examples. For process technology, one of the biggest obstacles is long-term stable contacts. Several device structures have been electrically characterized at high temperature (BJTs and FETs) and will be compared to surface temperature measurements and physical device simulation. Finally some proposed circuit topologies as well as novel solutions will be presented.
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| 2. |
- Ghandi, Reza, et al.
(författare)
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Experimental evaluation of different passivation layers on the performance of 3kV 4H-SiC BJTs
- 2010
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Ingår i: Materials Science Forum. - 0255-5476 .- 1662-9752. ; 645-648:Part 1-2, s. 661-664
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the electrical performance in terms of maximum current gain, ON-resistance and blocking capability has been compared for 4H-SiC BJTs passivated with different surface passivation layers. Variation in BJT performance has been correlated to densities of interface traps and fixed oxide charge, as evaluated through MOS capacitors. Six different methods were used to fabricate SiO2 surface passivation on BJT samples from the same wafer. The highest current gain was obtained for PECVD deposited SiO2 which was annealed in N2O ambient at 1100 degrees C during 3 hours. Variations in breakdown voltage for different surface passivations were also found, and this is attributed to differences in fixed oxide charge that can affect the optimum dose of the high voltage JTE termination.
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| 7. |
- Hellberg, C., et al.
(författare)
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Evidence and evidence gaps in assessments and interventions in areas related to social work research and practice - an overview of four evidence maps
- 2023
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Ingår i: European Journal of Social Work. - : Informa UK Limited. - 1369-1457 .- 1468-2664. ; 26:5
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Tidskriftsartikel (refereegranskat)abstract
- This overview of four evidence maps is based on systematic reviews of assessment and interventions in social work practice. The aim was to investigate the evidence and evidence gaps within four important areas for social work research and practice. Descriptive data on search strategies and domains were collected from four evidence maps, on Social Assistance, Substance Dependence, Care for older adults respectively for persons with disabilities. The scientific quality and scientific evidence were assessed. Key findings were summarised by analyzing and discussing common and specific elements in the evidence maps. The overview was undertaken in close collaboration between researchers with expertise in the field and a government agency. The overview identified both evidence and evidence gaps with respect to effects and experiences of interventions and assessment methods in four evidence maps. Evidence maps provide a comprehensive picture of the state of social services research and can thereby be of use to both researchers and practitioners, and in the production of evidence based social work.
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| 8. |
- Koo, S. -M, et al.
(författare)
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Simulation and Measurement of Switching Characteristics of 4H-SiC Buried-Gate JFETs
- 2003
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Ingår i: Materials Science Forum. - : Trans Tech Publications Inc.. - 0255-5476 .- 1662-9752. ; 433-436, s. 773-776
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Tidskriftsartikel (refereegranskat)abstract
- Buried-gate junction field-effect transistors (JFETs) have been fabricated in 4H polytype silicon carbide (SiC). The dynamic switching characteristics of the JFETs in a circuit with inductive load have been characterized. The drain voltage rise/fall time of ∌30 ns and 25 ns have been observed for turn-off and turn-on, respectively. The results have been compared to numerical mixed-mode circuit simulations with finite element structures.
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