APPLICATIONS OF IN-SITU ELLIPSOMETRY TO MICROWAVE ELECTRON-CYCLOTRON-RESONANCE PLASMA PROCESSES

In situ static spectroscopic ellipsometry used during a process is a powerful method for characterizing the optical properties and structure of multilayered thin films. However, the commonly practiced rotating element ellipsometry takes about 10 min for each spectral measurement. Using only a single wavelength gives less information, but each measurement time reduces to about 5 s. It is shown that a combination of the techniques was adequate to investigate the plasma processes. Spectroscopic ellipsometry measurements for Si, Ge, InP, InSb, and GaAs showed that for properly selected photon energy ranges, the dependence of the dielectric functions on temperature is minimum while the sensitivity to surface modifications is high. The electron cyclotron resonance (ECR) plasma oxidation of Si is discussed first, since it is the simplest case, and then attention is given to more complex example of ECR plasma ion bombardment induced oxidation and damage in single crystal Ge.