[Application of LIBS in Element Analysis of Nanometer Thin Film Prepared on Silicon Basement]

In order to develop a method to analyze the metal elements in the thin film samples rapidly, directly and without sample preparation, a laboratory LIBS system was established recently for nanometer film analysis. This system could determine the position of sample plane, observe the profiles of sample after pulse-material interaction and detect the plasma morphologyand spectral emission at the same time. Samplesused were ZrO2 films about 40 nm thickness prepared on Si by a sol-gel process, and they were located on a manual X-Y-Z translational stage with theaccuracy of 0. 01 mm. Final results showed that the positional accuracy is about 20µLm with the help of two CW lasers, and the RSD of repeatability of single-shot spectra could be to 1. 6%. We investigated special morphology of plasma, variation tendency of signal intensity as a function of pulse energy, LTSD (laser focus to sample distance) and time, which provide cornerstone for optimizing experimental parameters under the conditions of room temperature and atmospheric pressure. We calculated plasma temperature by way of Boltzmann curve and electron density through the acquired data. We also appraised necessary LTE conditions for quantitativeanalysis.