表面氧化层效应对测量临界点跃迁的影响:分数维空间方法

Oxide overlayer effect on the measurement of the parameters of interband critical point: A fractional-dimensional space approach

运用椭偏技术和分数维空间方法 ,对Si_SiO2 模型考察了表面氧化层的存在对从实验测得的光谱中确定Si临界点跃迁参数的影响 .计算结果表明 ,表面氧化层效应使Si的介电谱发生畸变 ,由此得到的临界点跃迁参数较真值会有一个偏移 :振幅与维度值较小 ,寿命线宽较大 ,并且这种影响随氧化层厚度的增加而加强 .但禁带能受表面氧化层效应的影响却很小 。

The fractional_dimensional space approach and analysis of spectroscopic ellipsometry are used to study an oxide overlayer effect on the measurement of the parameters of interband critical point (CP) of Si by a Si_SiO 2 model. The results of the calculation show that the oxide overlayer effect can influence the calculated CP parameters derived from an optical spectrum by decreasing the amplitude and dimensionality, and increasing the lifetime broadening. Moreover, the effect is enhanced with increasing thickness of the overlayer. However, this effect on threshold energy is shown to be very small and can be ignored.