Novel analysis system using surface desorption stimulated by VUV photons from laser-produced plasma

摘要

We proposed and developed a novel surface analysis system using vacuum ultraviolet (VUV) photons. When the VUV photons were irradiated on the material surface, surface desorption was stimulated. The desorbed species were analyzed by the mass spectrometer. First, we studied the decomposition process induced by VUV photons from excimer lamps. We found that the different photon energy resulted in the different time dependence of the fragments signals even if the materials had similar chemical construction. It suggested that the identification of the materials should be possible by tracing the decomposition process. We developed an analyzing system, called "Photo-Stimulated Desorption (PSD) mass spectrometer" using a broadband VUV radiation from the Ar plasma excited by a Q-switched Nd:YAG laser. The desorbed species were analyzed by the quadrupole mass spectrometer. This PSD system was useful surface analysis tool not only for the semiconductor but also plastics, which is easily affected by heat.