High-peak-power pulse laser for laser-induced breakdown

Using light (photons) as a means to measure various kinds of physical quantities in their normal environment has the advantage of real-time and precise measurement without interference from other objects. In the semiconductor process, for example, the measurement limit of particle size is down to 0.1 micrometer and the measurement of elements that the particles are composed of is impossible. Presently, there is only one measuring instrument that can measure the elements and diameter of particles at the same time by putting particles in microwave induced He plasma. However, the minimum size with which particles of hydrocarbon material can be measured is limited to several micrometer by this method. This method can not be applied to the measurement of sub-micron particles, which is important to the semiconductor process and for functional particles. The Final goal of the research is to develop devices and systematization technology needed for the newly proposed particle measurement technology using laser induced breakdown (LIB). In particle Measurement using LIB, indispensable high peak, power pulse laser (HPPL) for breakdown generation, ultraviolet fiber for passing fluorescence light and a high speed photo detection device having sub-micro second time resolution are needed. Furthermore, it is necessary to develop systematization technology and obtain final system evaluation when using these device technologies. In this paper, we mainly report on the experimental results of High Peak Power Laser (HPPL) for LIB and its basic consideration in the fiscal year 1999.