TY - JOUR
T1 - Formation of β-FeSi2-xGex by Ge-segregation-controlled solid-phase growth of [a-Si/a-FeSiGe]n multilayered structure
AU - Sadoh, Taizoh
AU - Owatari, Masakazu
AU - Murakami, Yuji
AU - Kenjo, Atsushi
AU - Yoshitake, Tsuyoshi
AU - Itakura, Masaru
AU - Miyao, Masanobu
PY - 2004/4
Y1 - 2004/4
N2 - The solid-phase growth of [a-Si/a-Fe0.4Si0.5Ge 0.1]n (n = 1, 2, 4; total thickness: 500 nm) multilayered structures has been investigated. After annealing at 700°C, [a-SiGe/polycrystalline β-FeSi2-xGex]n (x = 0.5, 0.4, 0.2 for n = 1, 2, 4, respectively) multilayered structures were formed. From the analysis of X-ray diffraction spectra, it was found that the lattice constants of β-FeSi1.5Ge0.5 changed from those of relaxed β-FeSi2 by 0.4-0.5%. The change decreased with increasing n, which was due to the segregation of Ge atoms from the a-Fe 0.4Si0.5Ge0.1 layers to the a-Si layers becoming larger with increasing n. After annealing at 800°C, Ge atoms were completely swept out from the β-FeSi2-xGex lattice. In addition, the agglomeration of βFeSi2 occurred, and nanocrystals of relaxed β-FeSi2 and c-Si0.7Ge 0.3 were formed. This technique for the formation of βFeSi 2-xGex is expected to be useful for energy gap modulation for advanced optoelectrical devices.
AB - The solid-phase growth of [a-Si/a-Fe0.4Si0.5Ge 0.1]n (n = 1, 2, 4; total thickness: 500 nm) multilayered structures has been investigated. After annealing at 700°C, [a-SiGe/polycrystalline β-FeSi2-xGex]n (x = 0.5, 0.4, 0.2 for n = 1, 2, 4, respectively) multilayered structures were formed. From the analysis of X-ray diffraction spectra, it was found that the lattice constants of β-FeSi1.5Ge0.5 changed from those of relaxed β-FeSi2 by 0.4-0.5%. The change decreased with increasing n, which was due to the segregation of Ge atoms from the a-Fe 0.4Si0.5Ge0.1 layers to the a-Si layers becoming larger with increasing n. After annealing at 800°C, Ge atoms were completely swept out from the β-FeSi2-xGex lattice. In addition, the agglomeration of βFeSi2 occurred, and nanocrystals of relaxed β-FeSi2 and c-Si0.7Ge 0.3 were formed. This technique for the formation of βFeSi 2-xGex is expected to be useful for energy gap modulation for advanced optoelectrical devices.
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U2 - 10.1143/JJAP.43.1879
DO - 10.1143/JJAP.43.1879
M3 - Article
AN - SCOPUS:3142609301
SN - 0021-4922
VL - 43
SP - 1879
EP - 1881
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
IS - 4 B
ER -