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Andersson, Sven
Alternative names
Publications (10 of 10) Show all publications
Chubarov, M., Pedersen, H., Högberg, H., Czigany, Z., Andersson, S. G. & Henry, A. (2014). Nucleation and initial growth of sp2-BNon α-Al2O3 and SiC by chemical vapour deposition.
Open this publication in new window or tab >>Nucleation and initial growth of sp2-BNon α-Al2O3 and SiC by chemical vapour deposition
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2014 (English)Manuscript (preprint) (Other academic)
Abstract [en]

Knowledge on thin films evolution from the early stages of growth is important for the control of quality and properties of the film. Here we present study of the early growth stages and evolution of the crystalline structure of sp2 hybridised Boron Nitride (BN) thin films deposited by chemical vapour deposition from triethyl boron and ammonia. Nucleation of hexagonal BN (h-BN) is observed already at 1200 °C on α-Al2O3 substrate with an AlN buffer layer (AlN/α-Al2O3) while no formation of h-BN is detected when the growth is done on 6H-SiC in a growth temperature range between 1200 °C and 1700 °C. We demonstrate that h-BN grows on AlN/α-Al2O3 exhibiting a layer-by-layer growth mode up to ca. 4 nm followed by a transition to r-BN growth when grown at 1500 °C. The following r-BN growth is suggested to proceed with mixed layer-by-layer and island growth mode; after a thin continuous layer of r-BN, islands formation is favoured leading to a twinned r-BN structure of the film. We find that h-BN does not grow on 6H-SiC substrates instead r-BN nucleates and grows directly as a twinned crystal. The twinning is found to be suppressed by a surface preparation of the SiC substrate with SiH4 prior to BN growth. These results open up for a more controlled epitaxial growth of sp2-BN for future electronic applications.

National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-112578 (URN)
Available from: 2014-12-04 Created: 2014-12-04 Last updated: 2015-03-11Bibliographically approved
Leone, S., Pedersen, H., Beyer, F., Andersson, S., Kordina, O., Henry, A., . . . Janzén, E. (2012). Chloride-Based CVD of 4H-SiC at High Growth Rates on Substrates with Different Off-Angles. In: Materials Science Forum Vols 717 - 720. Paper presented at 14th International Conference on Silicon Carbide and Related Materials (ICSCRM 2011), 11-16 September 2011, Cleveland, OH, USA (pp. 113-116). Trans Tech Publications Inc., 717-720
Open this publication in new window or tab >>Chloride-Based CVD of 4H-SiC at High Growth Rates on Substrates with Different Off-Angles
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2012 (English)In: Materials Science Forum Vols 717 - 720, Trans Tech Publications Inc., 2012, Vol. 717-720, p. 113-116Conference paper, Published paper (Refereed)
Abstract [en]

A review of recently achieved results with the chloride-based CVD on 8 degrees and 4 degrees off-axis and nominally on-axis 4H-SiC wafers is done to clarify the epitaxial growth mechanisms on different off-angle substrates. The process conditions selected for each off-axis angle become even more difficult when running at growth rates of 100 mu m/h or more. A fine-tuning of process parameters, mainly temperature, C/Si ratio and in situ surface preparation is necessary for each Wangle. Some trends related to the surface properties and the effective C/Si ratio existing on the surface prior to and during the epitaxial growth can be observed.

Place, publisher, year, edition, pages
Trans Tech Publications Inc., 2012
Keywords
Chloride-based CVD; homoepitaxial growth; substrate off-angle; high growth rate
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-87566 (URN)10.4028/www.scientific.net/MSF.717-720.113 (DOI)000309431000026 ()
Conference
14th International Conference on Silicon Carbide and Related Materials (ICSCRM 2011), 11-16 September 2011, Cleveland, OH, USA
Available from: 2013-01-18 Created: 2013-01-18 Last updated: 2015-03-11
Li, X., Leone, S., Andersson, S., Kordina, O., Henry, A. & Janzén, E. (2012). CVD Heteroepitaxial Growth of 3C-SiC on 4H-SiC (0001) Substrates. In: Materials Science Forum Vols 717 - 720. Paper presented at 14th International Conference on Silicon Carbide and Related Materials (ICSCRM 2011), 11-16 September 2011, Cleveland, OH, USA (pp. 189-192). Trans Tech Publications Inc., 717-720
Open this publication in new window or tab >>CVD Heteroepitaxial Growth of 3C-SiC on 4H-SiC (0001) Substrates
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2012 (English)In: Materials Science Forum Vols 717 - 720, Trans Tech Publications Inc., 2012, Vol. 717-720, p. 189-192Conference paper, Published paper (Refereed)
Abstract [en]

This study has been focused on 3C-SiC epitaxial growth on 4H-SiC (0001) on-axis substrates using the standard CVD chemistry. Several growth parameters were investigated, including growth temperature, in-situ etching process and C/Si ratio. High quality single domain 3C epilayers could be obtained around 1350 degrees C, with propane present during pre-growth etching and when the C/Si ratio was equal to 1. The best grown layer is 100% 3C-SiC and single domain. The net n-type background doping is around 2x10(16) cm(-3). The surface roughness of the layers from AFM analysis is in the 3 to 8 nm range on a 50x50 mu m(2) area.

Place, publisher, year, edition, pages
Trans Tech Publications Inc., 2012
Keywords
heteroepitaxial growth; CVD; 3C-SiC
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-87569 (URN)10.4028/www.scientific.net/MSF.717-720.189 (DOI)000309431000045 ()
Conference
14th International Conference on Silicon Carbide and Related Materials (ICSCRM 2011), 11-16 September 2011, Cleveland, OH, USA
Available from: 2013-01-18 Created: 2013-01-18 Last updated: 2014-10-08
Henry, A., Leone, S., Beyer, F., Pedersen, H., Kordina, O., Andersson, S. & Janzén, E. (2012). SiC epitaxy growth using chloride-based CVD. Physica. B, Condensed matter, 407(10), 1467-1471
Open this publication in new window or tab >>SiC epitaxy growth using chloride-based CVD
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2012 (English)In: Physica. B, Condensed matter, ISSN 0921-4526, E-ISSN 1873-2135, Vol. 407, no 10, p. 1467-1471Article in journal (Refereed) Published
Abstract [en]

The growth of thick epitaxial SiC layers needed for high-voltage, high-power devices is investigated with the chloride-based chemical vapor deposition. High growth rates exceeding 100 mu m/h can be obtained, however to obtain device quality epilayers adjustments of the process parameters should be carried out appropriately for the chemistry used. Two different chemistry approaches are compared: addition of hydrogen chloride to the standard precursors or using methyltrichlorosilane, a molecule that contains silicon, carbon and chlorine. Optical and electrical techniques are used to characterize the layers.

Place, publisher, year, edition, pages
Elsevier, 2012
Keywords
Silicon carbide, Chloride, Epitaxy, Doping, PL, DLTS
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-77522 (URN)10.1016/j.physb.2011.09.063 (DOI)000303149600004 ()
Note
Funding Agencies|The Swedish Energy Agency||Swedish Research Council||Available from: 2012-05-28 Created: 2012-05-22 Last updated: 2017-12-07
Andersson, C. M., Ejebjörk, N., Henry, A., Andersson, S., Janzén, E., Zirath, H. & Rorsman, N. (2011). A SiC Varactor With Large Effective Tuning Range for Microwave Power Applications. IEEE ELECTRON DEVICE LETTERS, 32(6), 788-790
Open this publication in new window or tab >>A SiC Varactor With Large Effective Tuning Range for Microwave Power Applications
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2011 (English)In: IEEE ELECTRON DEVICE LETTERS, ISSN 0741-3106, Vol. 32, no 6, p. 788-790Article in journal (Refereed) Published
Abstract [en]

SiC Schottky diode varactors have been fabricated for use in microwave power applications, specifically the dynamic load modulation of power amplifiers. A custom doping profile has been employed to spread the C(V) over a large bias voltage range, thereby increasing the effective tuning range under large voltage swing conditions. The small-signal tuning range is approximately six, and punch through is reached at a bias voltage of -60 V, while the breakdown voltage is on the order of -160 V. An interdigitated layout is utilized together with a self-aligned Schottky anode etch process to improve the Q-factor at 2 GHz, which is 20 at zero bias and approximately 160 at punch through.

Place, publisher, year, edition, pages
IEEE Institute of Electrical and Electronics, 2011
Keywords
Interdigitated, load modulation, power amplifiers (PAs), Schottky diodes, self-aligned, SiC, tuning range, varactors
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-68914 (URN)10.1109/LED.2011.2131117 (DOI)000290994800030 ()
Available from: 2011-06-10 Created: 2011-06-10 Last updated: 2014-10-08
Henry, A., Leone, S., Beyer, F. C., Andersson, S., Kordina, O. & Janzén, E. (2011). Chloride based CVD of 3C-SiC on (0001) α-SiC substrates. In: Materials Science Forum Vols. 679-680 (2011) pp 75-78. Paper presented at ECSCRM 2010, Oslo, Norway (pp. 75-78). Trans Tech Publications Inc.
Open this publication in new window or tab >>Chloride based CVD of 3C-SiC on (0001) α-SiC substrates
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2011 (English)In: Materials Science Forum Vols. 679-680 (2011) pp 75-78, Trans Tech Publications Inc., 2011, p. 75-78Conference paper, Published paper (Refereed)
Abstract [en]

A chloride-based chemical-vapor-deposition (CVD) process has been successfully used to grow very high quality 3C-SiC epitaxial layers on on-axis α-SiC substrates. An accurate process parameters study was performed testing the effect of temperature, surface preparation, precursor ratios, nitrogen addition, and substrate polytype and polarity. The 3C layers deposited showed to be largely single-domain material of very high purity and of excellent electrical characteristics. A growth rate of up to 10 μm/h and a low background doping enable deposition of epitaxial layers suitable for MOSFET devices.

Place, publisher, year, edition, pages
Trans Tech Publications Inc., 2011
Keywords
epitaxial growth, chloride-based CVD, on-axis, 3C-SiC
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-73587 (URN)10.4028/www.scientific.net/MSF.679-680.75 (DOI)
Conference
ECSCRM 2010, Oslo, Norway
Available from: 2012-01-09 Created: 2012-01-09 Last updated: 2014-10-08
Leone, S., Lin, Y.-C., Beyer, F. C., Andersson, S., Pedersen, H., Kordina, O., . . . Janzén, E. (2011). Chloride-Based CVD at High Rates of 4H-SiC on On-Axis Si-Face Substrates. In: Materials Science Forum Vols. 679-680 (2011) pp 59-62. Paper presented at ECSCRM2010, Oslo, Norway (pp. 59-62). Trans Tech Publications Inc.
Open this publication in new window or tab >>Chloride-Based CVD at High Rates of 4H-SiC on On-Axis Si-Face Substrates
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2011 (English)In: Materials Science Forum Vols. 679-680 (2011) pp 59-62, Trans Tech Publications Inc., 2011, p. 59-62Conference paper, Published paper (Refereed)
Abstract [en]

The epitaxial growth at 100 µm/h on on-axis 4H-SiC substrates is demonstrated in this study. Chloride-based CVD, which has been shown to be a reliable process to grow SiC epitaxial layers at rates above 100 µm/h on off-cut substrates, was combined with silane in-situ etching. A proper tuning of C/Si and Cl/Si ratios and the combination of different chlorinated precursors resulted in the homoepitaxial growth of 4H-SiC on Si-face substrates at high rates. Methyltrichlorosilane, added with silane, ethylene and hydrogen chloride were employed as precursors to perform epitaxial growths resulting in very low background doping concentration and high quality material, which could be employed for power devices structure on basal-plane-dislocation-free epitaxial layers.

Place, publisher, year, edition, pages
Trans Tech Publications Inc., 2011
Keywords
Chloride-Based CVD, Epitaxial Growth, High Growth Rate, On-Axis
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-73600 (URN)10.4028/www.scientific.net/MSF.679-680.59 (DOI)
Conference
ECSCRM2010, Oslo, Norway
Available from: 2012-01-10 Created: 2012-01-10 Last updated: 2015-03-11
Leone, S., Beyer, F., Pedersen, H., Andersson, S., Kordina, O., Henry, A. & Janzén, E. (2011). Chlorinated precursor study in low temperature CVD of 4H-SiC. Thin Solid Films, 519(10), 3074-3080
Open this publication in new window or tab >>Chlorinated precursor study in low temperature CVD of 4H-SiC
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2011 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 519, no 10, p. 3074-3080Article in journal (Refereed) Published
Abstract [en]

Low temperature chemical vapour deposition of SiC has gained interest in the last years for being less demanding in terms of reaction chamber lifetime, but also for allowing higher p-type dopant incorporation. Chloride-based CVD at low temperatures has been studied using chloromethane with tetrachlorosilane or silane, respectively and with or without controlled HCl addition. In this study we explore the use of methyltrichlorosilane (MTS) at growth temperatures significantly lower than what is commonly used for homoepitaxial growth of SiC. MTS is a molecule containing all the needed precursor atoms; its effects are compared to the standard CVD chemistry, consisting of silane, ethylene, and HCl.

Very different chemistries between the two precursor systems are proposed; in the case of MTS, C/Si ratios higher than 1 were required, however using the standard chemistry ratios lower than 1 were needed to obtain a defect-free epitaxial layer. We also demonstrate the need of using Cl/Si ratios as high as 15 to achieve a growth rate of 13 μm/h for 8° off-axis 4H-SiC epitaxial layers at 1300 °C. Limitations due to the low growth temperature are discussed in light of the experimental evidence on the growth mechanism as determined by the morphology degradation and the limited growth rate. Finally a comparison between the epilayers morphology obtained on 4H-SiC substrates with different off-cuts are presented, confirming the importance of lower C/Si ratios for 4° off-axis material and the inevitable growth of the cubic SiC polytype on on-axis substrates.

Place, publisher, year, edition, pages
Elsevier, 2011
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-60219 (URN)10.1016/j.tsf.2010.12.119 (DOI)000289174300013 ()
Available from: 2010-10-08 Created: 2010-10-08 Last updated: 2017-12-12
Leone, S., Henry, A., Andersson, S., Kordina, O. & Janzén, E. (2010). Optimization of a Concentrated Chloride-Based CVD Process for 4H–SiC Epilayers. Journal of the Electrochemical Society, 157(10), H969-H979
Open this publication in new window or tab >>Optimization of a Concentrated Chloride-Based CVD Process for 4H–SiC Epilayers
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2010 (English)In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 157, no 10, p. H969-H979Article in journal (Refereed) Published
Abstract [en]

Concentrated homoepitaxial growths of 4H–SiC was performed using a chloride-based chemical vapor deposition (CVD) process on different off-angle substrates (on-axis, 4 and 8° off-axis toward the [110] direction). A suitable combination of gas flow and process pressure is needed to produce the gas speed that yields an optimum cracking of the precursors and a uniform gas distribution for deposition over large areas. The use of low pressure and the addition of chlorinated precursors bring the added benefit of achieving higher growth rates. A systematic study of the gas speed's effect on the growth rate, uniformity, and morphology on the 4H–SiC epitaxial layers was performed. Growth rates in excess of 50  µm/h were achieved on 50 mm diameter wafers with excellent thickness uniformity (below 2% /mean without rotation of the substrate) and smooth morphology using only 1/10 of the typical gas carrier flow and process pressure demonstrating the feasibility of a concentrated chloride-based CVD process for 4H–SiC. Thermodynamic calculations showed that the improved thickness uniformity could be due to a more uniform gas phase composition of the silicon intermediates. The concentration of the SiCl2 intermediate increases by a factor of 8 at a reduced carrier flow, while all the other hydrogenated silicon intermediates decrease.

National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-60218 (URN)10.1149/1.3473813 (DOI)
Available from: 2010-10-08 Created: 2010-10-08 Last updated: 2017-12-12
Henry, A., ul-Hassan, J., Pedersen, H., Beyer, F., Bergman, P., Andersson, S., . . . Godignon, P. (2007). Thick epilayers for power devices. In: Materials Science Forum, vol. 556-557: . Paper presented at ECSCRM2006 (pp. 47). Trans Tech Publications
Open this publication in new window or tab >>Thick epilayers for power devices
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2007 (English)In: Materials Science Forum, vol. 556-557, Trans Tech Publications , 2007, p. 47-Conference paper, Published paper (Refereed)
Abstract [en]

Growth of thick epitaxial SiC layers needed for high power devices is presented for horizontal hot-wall CVD (HWCVD) reactors. We demonstrate thickness of epilayer of 100 μm and more with good morphology, low-doping with no doping variation through the whole thick layer and reasonable carrier lifetime which mainly depends on the substrate quality. Typical epidefects are described and their density can dramatically be reduced when choosing correctly the growth conditions as well as the polishing of the surface prior to the growth. The control of the doping and thickness uniformities as well as the run-to-run reproducibility is also presented. Various characterization techniques such as optical microscopy, AFM, reflectance, CV, PL and minority carrier lifetime have been used. Results of high-voltage SiC Schottky power devices are presented.

Place, publisher, year, edition, pages
Trans Tech Publications, 2007
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-38679 (URN)10.4028/www.scientific.net/MSF.556-557.47 (DOI)45296 (Local ID)45296 (Archive number)45296 (OAI)
Conference
ECSCRM2006
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2019-10-14
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