Measurement of the electric-optic index of thin films by using modulated ellipsometry

Abstract

The electro-optic index of PLZT thin films was measured by means of modulated ellipsometry. First the refractive index (n) and thickness ( d) were measured by reflecting ellipsometry method. Then the electric field was applied on the film, and the change of refraction (deltan) by was obtained by transmission ellipsometry method. Finally, the electro-optic index was calculated by the data of n, d, E and deltan. This instrument has high sensitivity. So it is suitable to measure the electro-optical property of the thin film. 利用调制式的椭偏仪测量了掺镧锆钛酸铅PLZT薄膜的电光系数.首先用反射椭偏测量的方法得到薄膜的折射率(n)和厚度(d),然后利用透射椭偏在线测量的功能,在样品上加电场(E),得到薄膜的折射率的改变δn. 最后用测量得到的厚度,折射率以及折射率的改变来计算薄膜的电光系数.该仪器的灵敏度很高,很适合较薄的膜层材料电光性质的测量.