用椭圆偏振光谱精确确定半导体材料临界点的位置  

Accurately determining the position of critical pointfor the semiconductors by ellipsometry spectra

作　　者：张淑芝[1] 张燕峰[1] 

机构地区：[1]山东大学光电系

出　　处：《半导体杂志》1998年第3期1-7,共7页

摘　　要：分析了波长调制反射谱，实际是介电函数对能量的一级微商。导出了弱电场调制反射谱与介电函数对能量的三级微商成正比，将ＭＯＣＶＤ方法生长的ＧａＩｎＰ以及掺Ｓｉ和掺Ｚｎ三个样品，用椭偏光谱法测量得到可见光区的介电函数谱，并求其一级和三级微商谱。将用于分析电反射谱的三点法推广用于分析介电函数的一级和三级微商谱，得到波长调制和弱电场调制反射谱的实验结果，并与介电函数谱的结果加以比较，使灵敏度和分辨率有很大提高。we point out that the wavelength modulated reflective spectrum essentially is the first derivative of dielectric functions with respect to the energy . It was derived that the modulated reflective spectrum of weak electric field is proportional to the third derivative of the dielectric functions with respect to the energy. The dielectric function spectra for GalnP and doped Si or Zn GaInP samples grown by MOCVD were obtained in the region of visible light by using the ellipsometric spectroscopy, and then the first and third derivative spectra were evaluated. Extending the three - point - scaling used in the analysis of the electric reflective spectrum, the first and third derivative spectra of the dielectric functions can be analyzed . The experimental results of reflective spectra of wavelength modulation and weak electric field modulation were obtained and compared with that of dielectric function spectra. The sensitivity and resolution ratio increase remarlkably.

关 键 词：椭圆偏振光谱 临界点 三点比 半导体材料 

分 类 号：TN304.01[电子电信—物理电子学]