TY - JOUR
T1 - A reliable method to grow vertically-aligned silicon nanowires by a novel ramp-cooling process
AU - Ho, Tzuen Wei
AU - Hong, Franklin Chau Nan
N1 - Funding Information:
We gratefully acknowledge support for this work from the National Science Council of Taiwan under grant NSC-99-2221-E-006-197-MY3 and the Bureau of Energy, Ministry of Economic Affairs, Taiwan , through Projects 101-D0204-2.
PY - 2012/8/1
Y1 - 2012/8/1
N2 - We have grown silicon nanowires (SiNWs) on Si (1 1 1) substrates by gold-catalyzed vapor-liquid-solid (VLS) process using tetrachlorosilane (SiCl 4 ) in a hot-wall chemical vapor deposition reactor. Even under the optimized conditions including H 2 annealing to reduce the surface native oxide, epitaxial SiNWs of 150-200 nm in diameter often grew along all four 〈1 1 1〉 family directions with one direction vertical and three others inclined to the surface. Therefore, the growth of high degree ordered SiNW arrays along [1 1 1] only was attempted on Au-coated Si (1 1 1) by a ramp-cooling process utilizing the liquid phase epitaxy (LPE) mechanism. The Au-coated Si substrate was first annealed in H 2 at 650 °C to form Au-Si alloy nanoparticles, and then ramp-cooled at a controlled rate to precipitate epitaxial Si seeds on the substrate based on LPE mechanism. The substrate was further heated in SiCl 4 /H 2 to 850 °C for the VLS growths of SiNWs on the Si seeds. Thus, almost 100% vertically-aligned SiNWs along [1 1 1] only could be reproducibly grown on Si (1 1 1), without using a template or patterning the metal catalyst. The high-density vertically-aligned SiNWs have good potentials for solar cells and nano-devices.
AB - We have grown silicon nanowires (SiNWs) on Si (1 1 1) substrates by gold-catalyzed vapor-liquid-solid (VLS) process using tetrachlorosilane (SiCl 4 ) in a hot-wall chemical vapor deposition reactor. Even under the optimized conditions including H 2 annealing to reduce the surface native oxide, epitaxial SiNWs of 150-200 nm in diameter often grew along all four 〈1 1 1〉 family directions with one direction vertical and three others inclined to the surface. Therefore, the growth of high degree ordered SiNW arrays along [1 1 1] only was attempted on Au-coated Si (1 1 1) by a ramp-cooling process utilizing the liquid phase epitaxy (LPE) mechanism. The Au-coated Si substrate was first annealed in H 2 at 650 °C to form Au-Si alloy nanoparticles, and then ramp-cooled at a controlled rate to precipitate epitaxial Si seeds on the substrate based on LPE mechanism. The substrate was further heated in SiCl 4 /H 2 to 850 °C for the VLS growths of SiNWs on the Si seeds. Thus, almost 100% vertically-aligned SiNWs along [1 1 1] only could be reproducibly grown on Si (1 1 1), without using a template or patterning the metal catalyst. The high-density vertically-aligned SiNWs have good potentials for solar cells and nano-devices.
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U2 - 10.1016/j.apsusc.2012.04.153
DO - 10.1016/j.apsusc.2012.04.153
M3 - Article
AN - SCOPUS:84862585283
SN - 0169-4332
VL - 258
SP - 7989
EP - 7996
JO - Applied Surface Science
JF - Applied Surface Science
IS - 20
ER -