| 1. |
- Achtziger, N, et al.
(författare)
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Formation of passivated layers in p-type SiC by low energy ion implantation of hydrogen
- 2000
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Ingår i: SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2. ; , s. 933-936
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Konferensbidrag (refereegranskat)abstract
- The mobility of hydrogen and its passivating effect on accepters in p-type SiC is investigated. Hydrogen (isotope H-1 or H-2 alternatively) is implanted at temperatures between 300 K and 680 K with low energy (300 eV per atom) in order to minimize implantation damage. The depth profiles of 2H and of passivated accepters correspond closely. Up to 500 K, a fully passivated layer with a well defined thickness is formed. Its depth ton the order of 1 micrometer) is investigated as a function of doping level and hydrogen fluence. At higher temperatures, the incorporation drastically increases, but the electrical passivation is partial only. Qualitative explanations are given.
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| 2. |
- Forsberg, Urban, et al.
(författare)
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Photoluminescence study of CVD layers highly doped with nitrogen
- 2000
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Ingår i: Materials Science Forum, Vols. 338-342. - 0878498540 ; , s. 619-622, s. 619-622
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Konferensbidrag (refereegranskat)abstract
- From a systematic study of highly doped n-type 4H-SiC epilayers we observe a photoluminescence spectrum, which was previously associated with the recombination of a bound exciton at the neutral boron acceptor. Electrical measurements performed on these layers show clearly n-type conductivity. It was feasible to dope and measure reproducibly the layers from low 10(17) to mid 10(18) cm(-3). It was not possible to determine the doping from Capacitance Voltage measurements for the samples grown with the highest doping (>6.10(18) cm(-3)). However Secondary Ion Mass spectrometry did not reveal any boron impurities in the layers and shows good agreement with electrical measurements regarding the nitrogen concentration.
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| 3. |
- Janson, M S, et al.
(författare)
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Channeled implants in 6H silicon carbide
- 2000
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Ingår i: SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2. ; , s. 889-892
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Konferensbidrag (refereegranskat)abstract
- Implants of MeV B-11, Al-27 and Ga-69 into the <0001> channel of 6H-SiC have been performed and concentration versus depth profiles have been obtained utilizing secondary ion mass spectrometry (SIMS). The experiment shows that the deepest channeled Ga ions reach a depth of 6.6 mum, which is 4 times deeper than the projected range of a random angle implantation, while the deepest channeled B ions only exceed the random projected range by 40%. Measurements at several implantation fluences show that implantation induced damage quench the deep channeling at fluences around 2 and 10x10(13) cm(-2) for Al and Ga, respectively, while only a minor fluence dependence is found in the B implants at fluences up to 2.6x10(14) cm(-2). The ion mass dependence of these effects is explained by the electronic to nuclear stopping ratios. Monte Carlo simulations of the channeling implants have also been performed and good agreements are found between simulations and experimental data.
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| 4. |
- Linnarsson, M K, et al.
(författare)
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Metal-contact enhanced incorporation of deuterium in 4H-and 6H-SiC
- 2000
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Ingår i: Materials Science Forum. - 0255-5476 .- 1662-9752. ; 338-3, s. 937-940, s. 937-940
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Tidskriftsartikel (refereegranskat)abstract
- Deuterium was introduced in p-type SiC from a gas ambient. The samples were partially coated with 200 Angstrom thick metal layer of titanium, nickel, platinum or gold. Heat treatments were performed in the temperature range 500-800 degreesC during 4 h. Secondary ion mass spectrometry (SIMS) was used to measure the deuterium content after deuterium exposure. The catalytic metal coating is shown to play an important role for introducing deuterium into SiC. Nickel and platinum facilitate hydrogen incorporation in p-type SiC, which may be due to an increased hydrogen concentration at the metal/SiC interface and/or an increase the H+ ions to H ratio. No in-diffusion of deuterium is observed using titanium although large quantities of deuterium are stored in the titanium film. Furthermore, gold reveals an inert character and does not promote in-diffusion of deuterium.
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| 5. |
- Syväjärvi, Mikael, et al.
(författare)
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High growth rate epitaxy of thick 4H-SiC layers
- 2000
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Ingår i: Materials Science Forum, Vols. 338-342. - : Scientific.Net. ; , s. 165-168, s. 165-168
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Konferensbidrag (refereegranskat)abstract
- Sublimation epitaxy for fabrication of thick 4H-SiC layers has been studied with respect to surface morphology, structural quality, and purity. The surface morphology of thick (50-100 mum) epilayers is smooth, even though the growth rate was 100 mum/h. These surfaces are obtained within a parameter window for morphological stability. The structural perfection is confirmed by high-resolution X-Ray diffraction measurements and the epilayer quality is improved compared with the substrate. The limitation in purity is dependent mainly on the purity of the SiC source material. The growth system purity, mainly graphite and Ta parts of the growth crucible, is also of major importance. Results from intentional doping for high-resistive, semi-insulating and p-type material are presented.
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