Spectroscopic study of vapor-phase reactions in preparation of YBa₂Cu₃O_7-x oxide thin film using pulsed laser deposition

Vapor-phase reactions in plasma plume during preparation of YBa₂Cu₃O_7-x superconducting thin film are investigated using optical emission spectroscopy. Argon/oxygen gas mixtures of various ratios are used as ambient to study the formation of diatomic oxides. Most of YO and some of BaO molecules are formed in the vapor, while CuO molecules are not formed in the vapor but only ejected from the target. To obtain high-quality oxide thin films, fluxes of the oxide molecules, atoms and ions reaching a substrate, which are dependent on laser energy density, argon mixture ratio and total pressure, should be controlled.