TY - JOUR
T1 - Ion-beam irradiation effect on solid-phase growth of β-FeSi2
AU - Murakami, Y.
AU - Kido, H.
AU - Kenjo, A.
AU - Sadoh, T.
AU - Yoshitake, T.
AU - Miyao, M.
N1 - Funding Information:
A part of this work was supported by the Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology of Japan. The XRD measurements were performed by using SHIMADZU XD-D1 at the Center of Advanced Instrumental Analysis, Kyushu University.
PY - 2003/3
Y1 - 2003/3
N2 - Effects of Ar+ ion-beam irradiation on solid-phase growth of β-FeSi2 have been investigated. Fe (10 nm)/Si structures were irradiated with 25 keV Ar+(5.0 × 1015 cm-2) at a temperature of 25°C (sample A) or 400°C (sample B), and subsequently annealed at 800°C. A reference was obtained after annealing without irradiation (sample C). X-ray diffraction results indicated that β-FeSi2 was formed after annealing at 800°C for 5 h, and the formation rate was the fastest for sample A and the slowest for sample C, i.e., A > B≫C. However, Auger electron spectroscopy measurements showed that atomic mixing at Fe/Si interface before annealing was B > A≫C. These results suggested that amorphization of Si substrate, in addition to atomic mixing, enhanced the solid-phase growth of β-FeSi2, which was confirmed experimentally. Moreover, a direct band gap of 0.89 eV was observed for the sample with pre-amorphization by the Fourier-transform infrared (FT-IR) spectroscopy measurements. These enhancement effects were attributed to that the phase transition to β-FeSi2 was accelerated by atomic arrangement induced during annihilation of excess vacancies. These enhancement effects can be utilized for nano-fabrication of β-FeSi2 by using focused ion-beam irradiation.
AB - Effects of Ar+ ion-beam irradiation on solid-phase growth of β-FeSi2 have been investigated. Fe (10 nm)/Si structures were irradiated with 25 keV Ar+(5.0 × 1015 cm-2) at a temperature of 25°C (sample A) or 400°C (sample B), and subsequently annealed at 800°C. A reference was obtained after annealing without irradiation (sample C). X-ray diffraction results indicated that β-FeSi2 was formed after annealing at 800°C for 5 h, and the formation rate was the fastest for sample A and the slowest for sample C, i.e., A > B≫C. However, Auger electron spectroscopy measurements showed that atomic mixing at Fe/Si interface before annealing was B > A≫C. These results suggested that amorphization of Si substrate, in addition to atomic mixing, enhanced the solid-phase growth of β-FeSi2, which was confirmed experimentally. Moreover, a direct band gap of 0.89 eV was observed for the sample with pre-amorphization by the Fourier-transform infrared (FT-IR) spectroscopy measurements. These enhancement effects were attributed to that the phase transition to β-FeSi2 was accelerated by atomic arrangement induced during annihilation of excess vacancies. These enhancement effects can be utilized for nano-fabrication of β-FeSi2 by using focused ion-beam irradiation.
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U2 - 10.1016/S1386-9477(02)00641-0
DO - 10.1016/S1386-9477(02)00641-0
M3 - Conference article
AN - SCOPUS:0037336985
SN - 1386-9477
VL - 16
SP - 505
EP - 508
JO - Physica E: Low-Dimensional Systems and Nanostructures
JF - Physica E: Low-Dimensional Systems and Nanostructures
IS - 3-4
T2 - Symposium H of the Spring Meeting of the Europe (E-MRS-02H)
Y2 - 18 June 2002 through 21 June 2002
ER -