A Practical Electrode for Microwave Plasma Processes

Abstract

In-liquid plasma chemical vapor deposition (CVD) method is useful for high speed production of high quality diamond films. The method is simple and secure comparing usual CVD methods. In this paper, new electrodes for in-liquid plasma CVD by receiving microwaves are developed and introduced. This paper examines the fabrication of electrodes that enable the generation of plasma by effectively receiving microwaves. The fabricated electrodes are used to generate plasma in a waste liquid and the performance of the electrode is evaluated by the speed at which gases are created by decomposing the liquid. By using experiments in decomposing n-dodecane using in-liquid plasma and through detailed investigation into the length of the electrode used, it is confirmed that the half wavelength is optimal for the generation of plasma. The fabri-cated electrodes are used to test the formation of diamond film by plasma CVD in the microwave oven. Diamond film is successfully created inside microwave oven by using the vapor from a mixture of methanol and ethanol.