Atomic and molecular spectra from electron-excited alkali halides

When a solid is bombarded with energetic charged particles, constituent atoms eject from the surface to outside of the solid. In recent years, this sputtering phenomenon has extensively been investigated because of its applicability to microfabrication. It has become common understanding that the electronic excitation plays a dominant role in the sputtering process. For example, electronic excitation of alkali halides leads to the ejection of halogen atoms preferentially along the direction of the crystal. However, there still remains several important problems we have to solve; how alkali atoms are sputtered, what happens in the surface layers after the sputtering of constituent atoms, and so on. The purpose of the present study is to solve these problems.