Analysis of bombardment effect of 10-to-100-keV C ions on a Si surface
10-100keV領域CイオンのSi表面に対する衝撃効果の解析
鳴海 一雅; 楢本 洋*; 高橋 康之; 山田 圭介; 千葉 敦也; 齋藤 勇一; 前田 佳均
Narumi, Kazumasa; Naramoto, Hiroshi*; Takahashi, Yasuyuki; Yamada, Keisuke; Chiba, Atsuya; Saito, Yuichi; Maeda, Yoshihito
In the energy range from 10 to 540 keV, we have determined Si sputtering yield as a function of energy of C ions, and the number density of Si atoms displaced from the lattice site and carbon concentration in the surface layer as a function of C-ion fluence. Small pieces of Si(100) wafer were irradiated with 10-, 50-keV C and 400-keV C ions. The fluence of the C ion was 10 to 10 C/cm. The number of Si atoms displaced from their lattice sites per cm was determined from the peak area of a surface peak of backscattering yields of 2-MeV He ions for 100-axial alignment of a Si crystal. Carbon concentration in the surface layer was determined with the nuclear reactions C (d, p)C using 1.2-MeV D. Another set of Si samples were irradiated with 200-keV Ar ions at the fluence of 510 /cm prior to the C-ion irradiation in order to prepare an amorphous layer at the surface; then, they were irradiated with 10120-keV C and 200540-keV C ions. Si sputtering yields were determined from the thickness change of the amorphous layer measured with Rutherford-backscattering spectrometry using 2-MeV He ions. Effect of C-ion bombardment on a Si surface will be discussed comprehensively.