Chemical vapor deposition and composition-depth profiling of a graded coating by Auger electron spectroscopy used in conjunction with taper polishing

A graded TiCxN1−x coating with x varying parabolically in the range 0-1 was grown by chemical vapor deposition in the TiCL4-CH4-N2-H2 system by quasi-continuously changing process parameters (growth time, CH4 mole fraction) at 1400 K and at 10.7 kPa. Taper polishing of the graded coating was carried out by a simple apparatus converting a depth dimension into a lateral dimension. Auger electron spectroscopy line scan was then performed on the taper polished surface. Composition profile of the graded coating was determined to be in agreement with the designed one using surface profilometer traces and AES signals from CKLL transition at 272 eV. AES/taper polishing approach facilitates composition-depth analysis with a minimal degree of sputtering and a substantial reduction of data acquisition time. Taper polishing could also be combined with other chemical analysis techniques such as X-ray microdiffraction.