Abstract

High energy photons above 5eV have attracted much attention, because of their feasibility for opening doors towards new phenomena in laser material processings. In fact, we have recently shown that VUV photons have an ability to break bonds between Si-O in quartz glass and further to lead oxygen desorption and silicon precipitation. The phenomenon requires photons high enough to induce band-to-band transition (>9eV). The similar phenomenon has been confirmed to occur in Si₃N₄. With respect to the silicon precipitation mechanism, one of the most important and also interesting points is whether a thermal effect plays an important role or not in the process. In this paper, we show experimental results about the silicon precipitation when the samples are kept at room temperature (RT) and also at 500°C during the laser irradiation, and further discuss the mechanism based upon the results.

© 1995 IEEE