| 1. |
- Eless, V., et al.
(author)
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Controlling the carrier concentration of epitaxial graphene by ultraviolet illumination
- 2014
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In: SILICON CARBIDE AND RELATED MATERIALS 2013, PTS 1 AND 2. - Switzerland : Trans Tech Publications. - 9783038350101 ; , s. 1137-1141
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Conference paper (peer-reviewed)abstract
- Silicon carbide (SiC) is a well-known material for UV detection however the effect of UV illumination on the electron donation between the substrate, interfacial (or buffer layer) and graphene is not well understood. The effect of ultraviolet (UV) illumination on the carrier concentration of an epitaxial graphene hall bar device is investigated by scanning Kelvin probe microscopy (SKPM) and transport measurements in ambient and vacuum conditions. Modulation of the carrier concentration is demonstrated and shown to be due to both substrate and environmental effects.
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| 2. |
- Florentin, M., et al.
(author)
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Rapid thermal oxidation of Si-Face N and P-type on-axis 4H-SiC
- 2014
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In: SILICON CARBIDE AND RELATED MATERIALS 2013, PTS 1 AND 2. - : Trans Tech Publications. - 9783038350101 ; , s. 591-594
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Conference paper (peer-reviewed)abstract
- This paper deals with the comparison of several MOS structures with different rapid thermal oxidation processes (RTO) carried out on Off and On-axis SiC material. A first set contains MOS capacitance structures on n-epitaxial layers, while a second set of MOS capacitance are built on p-implanted layers. Both sets include On and Off-Axis angle cuts. Furthermore, n-MOSFETs have been fabricated on On-axis p-type Al-implanted layers with the best oxidation process selected from the MOS capacitance study. The final objective is to show the performances of these On-axis p-implanted n-MOSFETs and to evidence the associated lower surface roughness at the SiO2/SiC interface.
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| 3. |
- Issa, F., et al.
(author)
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Nuclear radiation detectors based on 4H-SiC p+-n junction
- 2014
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In: 15th International Conference on Silicon Carbide and Related Materials, ICSCRM 2013. - 9783038350101 ; , s. 1046-1049
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Conference paper (peer-reviewed)abstract
- Silicon carbide (SiC) radiation detectors were realized by 10B implantation into the metal contact in order to avoid implantation-related defects within the sensitive area of the 4H-SiC pn junction. No post implantation annealing was performed. Such detectors respond to thermal neutrons showing consistent counting rates as function of external reverse bias voltages and radiation intensity.
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| 4. |
- Kallinger, B., et al.
(author)
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Comparison of carrier lifetime measurements and mapping in 4H SIC using time resolved photoluminescence and μ-PCD
- 2014
-
In: SILICON CARBIDE AND RELATED MATERIALS 2013, PTS 1 AND 2. - Stafa-Zurich, Switzerland : Trans Tech Publications. - 9783038350101 ; , s. 301-304
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Conference paper (peer-reviewed)abstract
- Carrier lifetime measurements and wafer mappings have been done on several different 4H SiC epiwafers to compare two different measurement techniques, time-resolved photoluminescence and microwave induced photoconductivity decay. The absolute values of the decay time differ by a factor of two, as expected from recombination and measurement theory. Variations within each wafer are comparable with the two techniques. Both techniques are shown to be sensitive to substrate quality and distribution of extended defects.
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| 5. |
- Lanni, Luigia, et al.
(author)
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SiC Etching and Sacrificial Oxidation Effects on the Performance of 4H-SiC BJTs
- 2014
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In: Materials Science Forum. - : Trans Tech Publications Inc.. - 0255-5476 .- 1662-9752. - 9783038350101 ; 778-780, s. 1005-1008
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Journal article (peer-reviewed)abstract
- Performance of 4H-SiC BJTs fabricated on a single 100mm wafer with different SiC etching and sacrificial oxidation procedures is compared in terms of peak current gain in relation to base intrinsic sheet resistance. The best performance was achieved when device mesas were defined by inductively coupled plasma etching and a dry sacrificial oxide was grown at 1100 °C.
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| 6. |
- Lim, Jang-Kwon, et al.
(author)
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Evaluation of buried grid JBS diodes
- 2014
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In: 15th International Conference on Silicon Carbide and Related Materials, ICSCRM 2013. - : Trans Tech Publications Inc.. - 9783038350101 ; , s. 804-807
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Conference paper (peer-reviewed)abstract
- The 4H-SiC Schottky barrier diodes for high temperature operation over 200 °C have been developed using buried grids formed by implantation. Compared to a conventional JBS-type SBD with surface grid (SG), JBS-type SBD with buried grid (BG) has significantly reduced leakage current at reverse bias due to a better field shielding of the Schottky contact. By introducing the BG technology, the 1.7 kV diodes with an anode area 0.0024 cm2 (1 A) and 0.024 cm2 (10 A) were successfully fabricated, encapsulated in TO220 packages, and electrically evaluated. Two types of buried grid arrangement with different grid spacing dimensions were investigated. The measured IV characteristics were compared with simulation. The best fit was obtained with an active area of approximately 60% and 70% of the anode area in large and small devices, respectively. The measured values of the device capacitances were 1000 pF in large devices and 100 pF in small devices at zero bias. The capacitance values are proportional to the device area. The recovery behavior of big devices was measured in a double pulse tester and simulated. The recovery charge, Qc, was 18 nC and 24 nC in simulation and measurement, respectively. The fabricated BG JBS-type SBDs have a smaller maximum reverse recovery current compared to the commercial devices. No influence of the different grid spacing on the recovery charge was observed.
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| 7. |
- Nee, Hans-Peter, 1963-, et al.
(author)
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High-Efficiency Power Conversion Using Silicon Carbide Power Electronics
- 2013
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In: Proc. of International Conference on silicon carbide and related materials (ICSCRM) 2013, Miyazaki, Japan, Sept. 29–Oct. 4, 2013. - : Trans Tech Publications Inc.. - 9783038350101 ; 778-780
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Conference paper (peer-reviewed)abstract
- The message of this paper is that the silicon carbide power transistors of today are good enough to design converters with efficiencies and switching speeds beyond comparison with corresponding technology in silicon. This is the time to act. Only in the highest power range the devices are missing. Another important step towards high powers is to find new solutions for multi-chip circuit designs that are adapted to the high possible switching speeds of unipolar silicon carbide power transistors.
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| 8. |
- Roensch, Sebastian, et al.
(author)
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Drain-current deep level transient spectroscopy investigation on epitaxial graphene/6H-SiC field effect transistors
- 2014
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In: Mater. Sci. Forum. - 9783038350101 ; , s. 436-439
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Conference paper (peer-reviewed)abstract
- The electrically active deep levels in a graphene/silicon carbide field effect transistor (FET) were investigated by drain-current deep level transient spectroscopy (ID-DLTS). An evaluation procedure for ID-DLTS is developed in order to obtain the activation energy, the capture cross section and the trap concentration. We observed three defect centers corresponding to the intrinsic defects E1/E2, Ei and Z1/Z2 in n-type 6H-SiC. The determined parameters have been verified by conventional capacitance DLTS.
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| 9. |
- Salemi, Arash, et al.
(author)
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Fabrication and Design of 10 kV PiN Diodes Using On-axis 4H-SiC
- 2014
-
In: Materials Science Forum. - : Trans Tech Publications. - 0255-5476 .- 1662-9752. - 9783038350101 ; 778-780, s. 836-840
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Journal article (peer-reviewed)abstract
- 10 kV PiN diodes using on-axis 4H-SiC were designed, fabricated, and measured. A lifetime enhancement procedure was done by carbon implantation followed by high temperature annealing to increase lifetime to above 2 mu s. The device simulation software Sentaurus TCAD has been used in order to optimize the diode. All fabricated diodes are fully functional and have a V-F of 3.3 V at 100 A/cm(2) at 25 degrees C, which was decreased to 3.0 V at 300 degrees C.
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| 10. |
- Sledziewski, Tomasz, et al.
(author)
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Reduction of density of 4H-SiC/SiO2 interface traps by pre-oxidation phosphorus implantation
- 2014
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In: Materials Science Forum. - 9783038350101 ; , s. 575-578
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Conference paper (peer-reviewed)abstract
- The effect of phosphorus (P) on the electrical properties of the 4H-SiC/SiO2 interface was investigated. Phosphorus was introduced by surface-near ion implantation with varying ion energy and dose prior to thermal oxidation. Secondary ion mass spectrometry revealed that only part of the implanted P followed the oxidation front to the interface. A negative flatband shift due to residual P in the oxide was found from C-V measurements. Conductance method measurements revealed a significant reduction of density of interface traps Dit with energy EC-Eit > 0.3 V for P+-implanted samples with [P]interface = 1.5 · 1018 cm-3 in the SiC layer at the interface. .
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