Quantification of the passivation and the selectivity in deposition process is disclosed. The passivation is evaluated by calculating film thicknesses on pattern lines and spaces. An XPS signal is used, which is normalized with X-ray flux number. The method is efficient for calculating thickness in selective deposition process, wherein the thickness can be used as metric to measure selectivity. Measured photoelectrons for each of the materials can be expressed as a function of the thickness of the material overlaying it, adjusted by material constant and effective attenuation length. In selective deposition over a patterned wafer, the three expressions can be solved to determine the thickness of the intended deposition and the thickness of any unintended deposition over passivated pattern.