電子穿越氮化銦及氮化鈦表面的非彈性交互作用之研究

Abstract

本論文根據電磁介電理論來研究電子穿越氮化銦及氮化鈦表面時，電子與固體間發生之非彈性交互作用。體激發效應及表面激發效應都對非彈性散射截面有所貢獻。在介電理論中，相關的激發效應可以用介電函式來描述，本論文利用實驗所量測到的光學數據來決定延伸式德魯特函式介電中的參數。接著計算入射或出射電子的微分倒數非彈性平均自由行徑及倒數非彈性平均自由行徑，並分析當電子以不同的電子能量、穿越角度、或離穿越點不同距離穿越氮化銦及氮化鈦表面時對微分倒數非彈性平均自由行徑及倒數非彈性平均自由行徑的影響。電子在固體外移動所產生激發的總機率可以用表面激發參數來詮釋，本研究也將計算電子入射或出射氮化銦及氮化鈦表面造成的表面激發參數，並分析當電子以不同的電子能量或不同穿越角度入射或出射氮化銦及氮化鈦表面時對表面激發參數的影響。

A dielectric response theory was used to study the inelastic cross sections for electrons crossing the indium nitride and titanium nitride surface. The inelastic cross sections contain information on both the surface and volume excitations. Parameters in the extended Drude dielectric function were determined from the fits of this function to experimental optical data. Theoretical derivations of the differential inverse inelastic mean free path (DIIMFP) and inverse inelastic mean free path (inverse IMFP) for either incident or escaping electrons were made for different electron energies, crossing angles, and electron distances relative to the crossing point at the surface. Dependences of the calculated DIIMFP and inverse IMFP on electron energy, crossing angle, and electron distance were analyzed. Surface excitation parameter (SEP), which describes the total probability of the surface excitations for the electrons moving outside the solid, was also calculated for different electron energies and crossing angles. The energy and angular dependences of the calculated SEPs were also analyzed.