| 1. |
- Intarasiri, S., et al.
(författare)
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Activation energy of the growth of ion-beam-synthesized nano-crystalline 3C-SiC
- 2007
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 257, s. 195-198
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Tidskriftsartikel (refereegranskat)abstract
- In this experiment, carbon ions at 40 keV were implanted into (10 0) high-purity p-type silicon wafers at 400 degrees C to a fluence of 6.5 x 10(17) ions/cm(2). Subsequent thermal annealing of the implanted samples was performed in a vacuum furnace at 800-1000 degrees C. Glancing incidence X-ray diffraction (GIXRD) was used to characterize the crystalline quality and estimate the grain size of nano-crystalline 3C-SiC. Activation energy for the growth of 3C-SiC was evaluated following the annealing behaviour of the GIXRD-characteristic 3C-SiC (111) peaks. It was found that the 3C-SiC was directly formed during ion implantation at this substrate temperature and the activation energy of the process was about 0.05 eV. Such a low energy was explained in terms of ion beam induced precipitate formation.
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| 2. |
- Intarasiri, S., et al.
(författare)
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RBS and ERDA determinations of depth distributions of high-dose carbon ions implanted in silicon for silicon-carbide synthesis study
- 2006
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 249, s. 859-864
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Tidskriftsartikel (refereegranskat)abstract
- For ion beam synthesis of silicon carbide (SiC), a knowledge of the depth distribution of implanted carbon ions in silicon is crucial for successful development. Based on its simplicity and availability, we selected Rutherford backscattering spectrometry (RBS) as an analysis technique for this purpose. A self-developed computer program dedicated to extract depth profiles of lighter impurities in heavier matrix is established. For control, calculated results are compared with an other ion beam analysis (IBA) technique superior for studying lighter impurity in heavier substrate i.e. elastic recoil detection analysis (ERDA). The RBS was performed with a 1.7-MV Tandetron accelerator using He2+ as the probe ions. The ERDA was performed with a 5-MV Pelletron accelerator using I8+ as the probe ions. This work shows that the RBS-extracted data had no significant deviations from those of ERDA and simulations by SRIM2003 and SIMPL computer codes. We also found that annealing at temperatures as high as 1000 degrees C had quite limited effect on the redistribution of carbon in silicon.
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| 3. |
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| 4. |
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| 5. |
- Intarasiri, S., et al.
(författare)
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Characterization of the crystalline quality of beta-SiC formed by ion beam synthesis
- 2006
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 249, s. 851-855
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Tidskriftsartikel (refereegranskat)abstract
- The ion beam synthesis (IBS) technique is applied to form crystalline silicon carbide (SiC) for future optoelectronics applications. Carbon ions at 80 and 40 keV were implanted into (100) high-purity p-type silicon wafers at room temperature and 400 degrees C, respectively, to doses in excess of 10(17) ions/cm(2). Subsequent thermal annealing of the implanted samples was performed in a vacuum furnace at temperatures of 800, 900 and 1000 degrees C, respectively. Elastic recoil detection analysis was used to investigate depth distributions of the implanted ions and infrared transmittance (IR) measurement was used to characterize formation of SiC in the implanted Si substrate. Complementary to IR, Raman scattering measurements were also carried out. Levels of the residual damage distribution of the samples annealed at different temperatures were compared with that of the as-implanted one by Rutherford backscattering spectrometry (RBS) in the channeling mode. The results show that C-ion implantation at the elevated temperature, followed by high-temperature annealing, enhances the synthesis of crystalline SiC.
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| 6. |
- Intarasiri, S., et al.
(författare)
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Crystalline quality of 3C-SiC formed by high-fluence C+-implanted Si
- 2007
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Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 253:11, s. 4836-4842
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Tidskriftsartikel (refereegranskat)abstract
- Carbon ions at 40 keV were implanted into (1 0 0) high-purity p-type silicon wafers at 400 degrees C to a fluence of 6.5 x 10(17) ions/cm(2). Subsequent thermal annealing of the implanted samples was performed in a diffusion furnace at atmospheric pressure with inert nitrogen ambient at 1100 degrees C. Time-of-flight energy elastic recoil detection analysis (ToF-E ERDA) was used to investigate depth distributions of the implanted ions. Infrared transmittance (IR) and Raman scattering measurements were used to characterize the formation of SiC in the implanted Si substrate. X-ray diffraction analysis (XRD) was used to characterize the crystalline quality in the surface layer of the sample. The formation of 3C-SiC and its crystalline structure obtained from the above mentioned techniques was finally confirmed by transmission electron microscopy (TEM). The results show that 3C-SiC is directly formed during implantation, and that the subsequent high-temperature annealing enhances the quality of the polycrystalline SiC.
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| 7. |
- Intarasiri, S., et al.
(författare)
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Ion beam synthesis of silicon carbide
- 2005
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Ingår i: PARTICLE BEAMS & PLASMA INTERACTION ON MATERIALS AND ION & PLASMA SURFACE FINISHING 2004. - 3908451124 ; , s. 51-54
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Konferensbidrag (refereegranskat)abstract
- Formation and crystallization of a thin near-surface layer of silicon carbide on a silicon substrate, created by ion-beam synthesis (IBS), are discussed. 80 and 40 keV carbon ions were implanted into a (100) high-purity p-type silicon substrate at roorn temperature and 400 degrees C, respectively, using doses in excess of 10(17) ions/cm(2). Elastic recoil detection analysis (ERDA) technique, developed for routine atomic depth profiling at the Angstrom laboratory, Uppsala University, Sweden, was used to investigate the depth distributions of implanted-ions. Infrared transmittance measurement was used as an indication of SiC in the implanted Si substrate. For the samples implanted at high temperature, the results show the existence of a peak at 797 cm(-1), indicating the presence of beta-SiC, already directly formed during the implantation without post-implantation annealing. While for the samples implanted at room temperature, starting with the band of amorphous Si-C network, the crystalline SiC appears at the annealing temperature as low as 900 degrees C. In both cases, during further annealing in vacuum, the peak grows in height and narrows in width (according to the measured FWHM) with increasing annealing temperature, indicating a further growth of the SiC layer. However, for thermal annealing at 1000 T in a vacuum furnace the SiC crystallization was not completed and crystal imperfection where still present. Complementary to IR, Raman scattering measurements were performed. Although no direct evidence of SiC vibrations were observed, the appearance and disappearance of both Si-Si and C-C related bands points out to the formation of silicon and carbon clusters in the implanted layer.
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| 8. |
- Intarasiri, Saweat, et al.
(författare)
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Effects of low-fluence swift iodine ion bombardment on the crystallization of ion-beam-synthesized silicon carbide
- 2007
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 101:8, s. 084311-
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Tidskriftsartikel (refereegranskat)abstract
- Ion beam synthesis using high-fluence carbon ion implantation in silicon in combination with subsequent or in situ thermal annealing has been shown to be able to form nanocrystalline cubic SiC (3C-SiC) layers in silicon. In this study, a silicon carbide layer was synthesized by 40-keV C 12 + implantation of a p -type (100) Si wafer at a fluence of 6.5× 1017 ions cm2 at an elevated temperature. The existence of the implanted carbon in Si substrate was investigated by time-of-flight energy elastic recoil detection analysis. The SiC layer was subsequently irradiated by 10-30 MeV I 127 ions to a very low fluence of 1012 ions cm2 at temperatures from 80 to 800 °C to study the effect on the crystallization of the SiC layer. Infrared spectroscopy and Raman scattering measurement were used to monitor the formation of SiC and detailed information about the SiC film properties was obtained by analyzing the peak shape of the Si-C stretching mode absorption. The change in crystallinity of the synthesized layer was probed by glancing incidence x-ray diffraction measurement and transmission electron microscopy was also used to confirm the results and to model the crystallization process. The results from all these measurements showed in a coherent way that the synthesized structure was a polycrystalline layer with nanometer sized SiC crystals buried in a-Si matrix. The crystallinity of the SiC layer was enhanced by the low-fluence swift heavy ion bombardment and also favored by higher energy, higher fluence, and higher substrate temperature. It is suggested that electronic stopping plays a dominant role in the enhancement.
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