Quantitative Analysis Using Dual Anode X‐Ray Photoelectron Spectroscopy

ABSTRACT Two methods enabling quantitative analysis on samples with complex morphology using dual‐anode X‐ray photoelectron spectroscopy (DAXPES) are presented. The first method calculates the thickness of thin films based on the peak area measured using X‐ray photoelectron spectroscopy (XPS) and hard X‐ray photoelectron spectroscopy (HAXPES). This technique has the advantage that peak deconvolution can be used if signals from both the thin film and substrate are observed in the same peak region (i.e., an oxide layer on a metal). However, it requires intensity calibrations and the instrumentation must allow for analysis of identical sample areas using each X‐ray source. The second method uses the ratio between the background intensities from single peak regions collected using soft and hard X‐rays to calculate the film thickness. The background‐based method does not require reference samples and is suitable for use on any instrument with both soft and hard X‐ray sources. Metrology measurements on discontinuous thin films made using single and dual X‐ray source methods can give complementary information, allowing a complete quantitative description of the sample in terms of thickness, coverage and composition. The DAXPES methods are also automatable, making them suitable for in‐line, on‐device measurements in the semiconductor industry.