One-dimensional model of discharge pumped excimer lasers

Abstract

For many excimer laser applications for example, in medicine and semiconductor processing, the long-term stability of the output pulse energy and the laser-beam profile are very important. The spatial intensity distribution of an excimer laser with a Fabry–Perot cavity depends on many discharge conditions (e.g., the loading voltage, the total gas pressure, the concentrations of the gas components, the repetition rate, the electrode profiles, and the spatial distribution of the preionization intensity). A one-dimensional model of a discharge pumped excimer laser is described. It can be shown that the laser output power of a KrF laser depends on the spatial variations of the discharge parameters to a higher degree than does a XeCl laser. The double structure of the transverse intensity distribution for long-term KrF laser operation can be explained as a consequence of the depletion of F2 concentration within the gas mixture after many discharges.