방사광 광전자 분광법을 이용한 Si_(1-x) Ge_(x)/Si(001) 합금의 전자구조에 관한 연구 = Study on Electronic Structure of Si_(1-x) Ge_(x)/Si(001) Alloys Using Synchrotron-Radiation Photoelectron Spectroscopy

다국어 초록 (Multilingual Abstract)

We investigated the evolution of Si 2p, Ge 3d core-level and valence-band photoemission spectra of disordered Si_(1) _(x)Ge_(x) alloys using synchrotron-radiation at room temperature. As Ge composition increases, the binding energy of the Si 2p (Ge 3d) is found to shift to low (high) energies. We performed a standard nonlinear least squares line-shape fitting to resolve surface and bulk contribution to the core-level spectra. The best fits were obtained with one bulk and two surface components. We observed Si 2p (Ge 3d) core-level binding energy shift to low (high) energies, increase (decrease) in the spin-orbit splitting, and decrease (increase) in the branching ratio for increasing Ge composition. The results are interpreted as due to bonding orbital difference of Si and Ge. As Ge composition increases, surface core-level binding energy shifts to low energies with decrease in the energy separation between top and second layer atoms. We also obtained valence band spectra of Si_(1) _(x)Ge_(x) alloys in various photon energies. Evolution of three well-separated peaks in the spectra indicated significant variation in the band structure of the alloy system.

목차 (Table of Contents)

• 목차
• ABSTRACT = 1
• Ⅰ. 서론 = 2
• Ⅱ. 이론 = 4
• 2.1 Photoemission의 원리 = 4
• 2.2 Core levels = 10
• 2.3 Valence bands = 16
• 2.4 Curve-fitting by Voigt peak function = 22
• Ⅲ. 실험 = 24
• Ⅳ. 결과 및 논의 = 27
• 4.1 Si 2p Core level 측정의 결과 및 논의 = 27
• 4.2 Ge 3d Core level 측정의 결과 및 논의 = 33
• 4.3 Valence Band의 결과 및 논의 = 38
• Ⅴ. 결론 = 43
• 참고문헌 = 45