Spectroscopic Study on a Discharge Plasma of MOCVD Source Gases for High-Tc Superconducting Films

Optical emission spectra from a glow-discharge plasma in the vapors of β-diketonate chelates of Ba, Y and Cu element have been measured. They show great changes depending on the temperature of the source-gas oven. In the case of Ba(DPM)2, for example, intensity of the Ba+ emission lines increases drastically at above 220°C, when compared to neutral lines. Referring to the data of thermal analysis and IR absorption experiment, this corresponds to the development of decomposition of the source material. The present experiment opens a future possibility of optical diagnostics to determine the optimum gas feeding condition in the preparation of high-T c superconducting films by the MOCVD technique.