| 1. |
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| 2. |
- Bergman, Peder, 1961-, et al.
(författare)
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Improved SiC Epitaxial Material for Bipolar Applications
- 2008
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Ingår i: Proc. of MRS Spring Meeting 2008. ; , s. D05-
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Konferensbidrag (refereegranskat)abstract
- Epitaxial growth on Si-face nominally on-axis 4H-SiC substrates has been performed using horizontal Hot-wall chemical vapor deposition system. The formation of 3C inclusions is one of the main problem with growth on on-axis Si-face substrates. In situ surface preparation, starting growth parameters and growth temperature are found to play a vital role in the epilayer polytype stability. High quality epilayers with 100% 4H-SiC were obtained on full 2″ substrates. Different optical and structural techniques were used to characterize the material and to understand the growth mechanisms. It was found that the replication of the basal plane dislocation from the substrate into the epilayer can be eliminated through growth on on-axis substrates. Also, no other kind of structural defects were found in the grown epilayers. These layers have also been processed for simple PiN structures to observe any bipolar degradation. More than 70% of the diodes showed no forward voltage drift during 30 min operation at 100 A/cm2.
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| 3. |
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| 4. |
- Brosselard, P, et al.
(författare)
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Comparison between 3.3kV 4H-SiC schottky and bipolar diodes
- 2008
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Ingår i: IET Seminar Digest, Volume 2008, Issue 2, 2008. - : IEE. - 9788001041390 ; , s. 87-91
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Konferensbidrag (refereegranskat)abstract
- Silicon Carbide Schottky and bipolar diodes have been fabricated with a breakdown voltage of 3.3kV. Diodes have been packaged and measured up to 300°C. The Schottky diode shows an increase of voltage drop with temperature and a reverse recovery charge independent from temperature. The PiN diode reverse recovery charge is ×20 at 300°C compared to that of the Schottky diode. 55% of the stressed bipolar diodes at 20A show a very small forward voltage drift. Theswitching losses of these stressed diodes are reduced by 20%. Substrate quality enhancement makes large SiC component fabrication possible (25mm 2 Schottky diodes) and bipolar components show very small tension drift with temperature.
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| 5. |
- Brosselard, P, et al.
(författare)
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High temperature behaviour of 3.5 kV 4H-SiC JBS diodes
- 2007
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Ingår i: Proceedings of the International Symposium on Power Semiconductor Devices and ICs. ; , s. 285-288
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Konferensbidrag (refereegranskat)abstract
- 4H-SiC JBS diodes have been manufactured on a Norstel epitaxied N/N + substrate using a JTE as edge termination. A breakdown voltage higherthan 3.5 kV has been measured on 0.16 and 2.56 mm 2 diodes. The leakage current in the 25°C-300°C temperature range depends on the bipolar/Schottky ratio whereas in forward mode its impact is minor. Diodes have been stressed in DC mode to show that the 2.56 mm 2 diodes have a slight forward voltage degradation independently of the layout. In switching mode, the recovery charge is only 20 nC for a 4A current switched at 300°C.
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| 6. |
- Brosselard, P, et al.
(författare)
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Low loss, large area 4.5 kV 4H-SiC PIN diodes with reduced forward voltage drift
- 2009
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Ingår i: SEMICONDUCTOR SCIENCE AND TECHNOLOGY. - : IOP Publishing. - 0268-1242 .- 1361-6641. ; 24:9, s. 095004-
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Tidskriftsartikel (refereegranskat)abstract
- 4H-SiC PIN diodes have been fabricated on a Norstel P+/N/N+ substrate with a combination of Mesa and JTE as edge termination. A breakdown voltage of 4.5 kV has been measured at 1 mu A for devices with an active area of 2.6 mm(2). The differential on-resistance at 15 A (600 A cm(-2)) was of only 1.7 m Omega cm(2) (25 degrees C) and 1.9 m Omega cm(2) at 300 degrees C. The reduced recovery charge was of 300 nC for a switched current of 15 A (500 V) at 300 degrees C. 20% of the diodes showed no degradation at all after 60 h of dc stress (25-225 degrees C). Other 30% of the diodes exhibit a reduced voltage shift below 1 V. For those diodes, the leakage current remains unaffected after the dc stress. Electroluminescence investigations reveal a very low density of stacking faults after the dc stress. The manufacturing yield evidences the efficiency of the substrate surface preparation and our technological process.
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| 7. |
- Florentin, M., et al.
(författare)
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Al-implanted on-axis 4H-SiC MOSFETs
- 2017
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Ingår i: Semiconductor Science and Technology. - : IOP PUBLISHING LTD. - 0268-1242 .- 1361-6641. ; 32:3
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the impact of temperature and time stress on gate oxide stability of several multi-implanted and epitaxied 4H-SiC nMOSFET is presented. The oxide layer was processed under a rapid thermal process (RTP) furnace. The variation of the main electrical parameters is shown. We report the high quality and stability of such implanted MOSFETs, and point out the very low roughness effect of the on-axis-cut sample. Particularly, in the best case, effective channel mobility (mu(fe)) overcomes 20 cm(2). V-1. s(-1) at 300 degrees C for a channel length of 12 mu m, which is very encouraging for implantation technology. Starting from 200 degrees C, the apparent increase of the mu(fe) peak of the MOSFET ceases and tends to saturate with further temperature increase. This is an indication of the potential of MOSFETs built on on-axis substrates. Thus, starting from the real case of an implanted MOSFET, the global purpose is to show that the electrical performance of such an on-axis-built device can tend to reach that of the ideal case, i.e. epitaxied MOSFET, and even overcome its electrical limitation, e.g. in terms of threshold voltage stability at high temperature.
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| 8. |
- Florentin, M., et al.
(författare)
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Rapid thermal oxidation of Si-Face N and P-type on-axis 4H-SiC
- 2014
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Ingår i: SILICON CARBIDE AND RELATED MATERIALS 2013, PTS 1 AND 2. - : Trans Tech Publications. - 9783038350101 ; , s. 591-594
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Konferensbidrag (refereegranskat)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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| 9. |
- Perez-Tomas, A, et al.
(författare)
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Schottky versus bipolar 3.3 kV SiC diodes
- 2008
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Ingår i: SEMICONDUCTOR SCIENCE AND TECHNOLOGY. - : IOP Publishing. - 0268-1242 .- 1361-6641. ; 23:12, s. 125004-
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Tidskriftsartikel (refereegranskat)abstract
- A comparative study of the electrical characteristics of 3.3 kV SiC Schottky barrier (SBD), junction bipolar Schottky (JBS) and PiN diodes is presented. 3.3 kV class 4H-SiC SBD, JBS and PiN diodes have been fabricated with an analogous technology process on similar epi wafers. Diodes have been characterized in forward, reverse and switching mode in the 25 degrees C - 300 degrees C temperature range. The optimum performance of the diodes depends on the adequate use of the unipolar or bipolar advantages and is established by the final application specifications. In this respect, a reverse recovery charge versus on-resistance diagram for different current densities is also presented. DC stress tests have been performed to investigate the forward voltage drift, related to the formation of stacking faults, during the bipolar mode of operation.
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| 10. |
- ul-Hassan, Jawad, 1974-, et al.
(författare)
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Non Degrading PiN Diodes Grown On On-axis 4H-SiC Substrates
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Bipolar PiN diodes have been fabricated using epitaxial layers grown on nominally onaxis Si-face 4H-SiC substrates. Top metal contacts were processed with windows to observe the electroluminescence and any formation of stacking faults during forward current injection. The diodes were tested for voltage stability using a forward current density of 120 A/cm2 for 30 min. More than 70 % of the diodes showed a stable behavior and change in the forward voltage was less than 0.1 V. No movement of basal plane dislocations or the formation of stacking faults was observed using electroluminescence. Most of the remaining diodes failed completely due to contact breakdown.
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