Optical Characterizations of Low-k Materials Using Forouhi-Bloomer Dispersion Equations

Accurate characterizations of low-k materials are very important in semiconductor manufacturing process.Traditional methods,such as scanning electron microscopy(SEM) and transmission electron microscopy(TEM) are both time-consuming and destructive.A new characterization technology on thin film was introduced to improve these disadvantages.Forouhi-Bloomer dispersion equations,combined with a broadband spectrophotometry,were used to measure the refractive index n,the extinction coefficient k and the thickness d of low-k films.Ellipsometer measurement was made for comparison.The results demonstrate that F-B equations are fitful to the accurate characterizations of low-k materials in semiconductor process and have advantages for the speed of measurement and nondestructive nature.