Optimization of convex electrode geometry for surface discharge used for fabrication of the electrode groove on solar cells

A low-cost plasma process technique for fabrication of electrode grooves on solar cells, in which the surface discharge operated at atmospheric pressure etched the silicon nitride film, was examined. Three kinds of dielectric electrodes of similar quality but of different shape and thickness were used, and the optimum electrode geometry was discussed. It was found that the suppression of the diffusion of radical species was a key to narrow the groove width and that a short term etching was necessary when the streamer length was long due to the geometry of the dielectric electrode.