Annealing process for recovery of carbonated (Mg,Ca)O protective layer for plasma discharge device

The carbonation behavior and decarbonation annealing of a protective (Mg, Ca)O layer for flat panel plasma discharge devices were investigated. Compared with a conventional MgO protective layer, the (Mg,Ca)O protective layer showed both high and low discharge voltages. Quantitative X-ray photoetectron spectroscopy analyses indicated that the high discharge voltages were caused by Ca carbonation. The progression of Ca carbonation was enhanced by exposure to air containing H2O but not by exposure to dry air. In addition, once (Mg,Ga)O is carbonated, it is impossible to decarbonate Ca by annealing in air at the temperature applied during the production process. We propose the use of annealing in vacuum as an effective method to promote the decarbonation of Ca and maintain a low discharge voltage for plasma discharge devices with (Mg,Ca)O protective layers. (C) 2018 The Japan Society of Applied Physics