纳米多孔氧化铝薄膜厚度的反射光谱测量方法研究

提出一种基于反射光谱的纳米多孔氧化铝(PA)薄膜厚度测量的方法。当白光照射PA薄膜时,分别从薄膜上、下表面反射的两束光线发生干涉。根据布拉格公式(B raggequation),若已知反射干涉光谱相邻两个极大值对应的波数差和薄膜的折射率就可以算出薄膜厚度。PA的有效折射率可根据M axw ell-G arnett有效介电常数理论由孔隙率算出。这种方法的优点是能实现PA总体膜厚的非接触、非破坏性在线测量。

A research of thickness measurement of nano-porous alumina films based on reflection spectrum

In this paper,we present a reflection spectrum method for measuring the thickness of nano-porous alumina(PA) films. When a white light beam illuminates the surface of PA film,the reflection light beams from the front and rear interfaces are coherent.By the Bragg equation,when the wave number difference between the two adjacent extrema from the reflection interference spectrum and the effective refractive index of the film are given,we can measure the thickness of PA film.The effective refractive index of the PA film is calculated from porosity given by Maxwell-Garnett effective dieletric constant theory.The advantages of this method include that it realizes non-contact and non-destructive,i.e.,on-line measurements of PA thickness.