Size distribution of droplets in film prepared by pulsed laser ablation

金沢大学工学部Volume and size distribution of droplets in oxide films were investigated for a variety of laser fluences, wavelengths and target temperatures. Effects of both the ambient gas pressure and the substrate temperature on the droplet formation was investigated. It was found that the increase in the ratio of the droplet volume to the film volume Vd/Vf caused by increasing the maximum etching depth of target per laser shot de (Vd/Vfde3, as previously reported) due to changes in the deposition conditions other than the target temperature is mainly attributed to an increase in the formation of large droplets. It was also found that the correlation Vd/Vfde3 is also valid for elevated target-temperatures, and the increase in the target temperature enhances the formation of small droplets compared with large ones. The effect of cooling of droplets after the ejection from the target due to the ambient pressure and/or the substrate temperature is discussed