Low-Temperature Sintering of Indium Tin Oxide Thin Film Using Split Gliding Arc Plasma

The feasibility of sintering on indium tin oxide (ITO) thin film by a mesoplasma under open atmosphere was investigated. An ITO film of 300 nm thickness was prepared on a glass substrate by spin coating an ITO nanoparticle suspension. A mesoplasma of a gliding arc was irradiated on the ITO film. The plasma generated a temperature of 160 °C at the irradiation position. By utilizing nitrogen (N2) gas as the plasma working fluid, the sheet resistance was effectively reduced, compared with the use of air. A small amount of hydrogen (H2) added was more effective. A conventional gliding arc (GA) caused film damage owing to the appearance of an arc spot on the treated film, although a split gliding arc (S-GA) was effectively treated without arc spot appearance and damage. A silica binder was added to the ITO nanoparticle suspension in order to increase film adhesion and conductivity by increasing the film density. A sheet resistance of 1.9 kΩ/sq was obtained at an optimum H2 concentration (1.0 vol %) in N2 and a silica binder concentration (12.5 vol %), which was similar to the resistance obtained by sintering the film on a hot plate at 300 °C.