DISCUSSION ON EXPERIMENTAL TECHNIQUES FOR X-RAY COMPUTED DEPTH PROFILING. Kun Tao and Jian Luo, Dept. of Materials Sci. & Engr., Tsinghua Univ., Beijing 10084, P.R.China

The experimental techniques for X-ray Computed Depth Profiling(CDP) method [J. Luo, H. Yin & K.Tao, Acta Physica Sinica(Chinese Edition), 44.1788; J.Luo & K.Tao, Acta Physica Sinica, 44.1793, J.Luo & K. Tao, Thin Solid Films, in press] are discussed. X-ray ploycrystalline diffraction data observed at various incident angles are used in determination of true phase-depth profiles for samples both with and without preferred orientation. Furthermore, numerical procedures are employed for solving the XRD patterns corresponding to every thin layer at arbitrary depth of a sample, which is similar to computed tomography technique. It has prospective application in determination of the true depth profiles of all structural information which can be obtained from X-ray peak intensity, peak position and line profile.

In the present paper, several selective topics were discussed in details. Determination of geometrical factor from a standard sample is discussed; different experimental methods and numerical procedures are compared; in addition, instrumentation and the scheme for samples with preferred orientation are also discussed.