Development of a wurtzite (Al,Ti)N thermistor on a resin substrate with high heat resistance

We developed a thin-film nitride thermistor on a resin substrate with high heat resistance by focusing on the interface between the polyimide (PI) substrate and (Al,Ti)N film. Heat resistance properties of nitride thermistors are degraded by an amorphous oxynitride layer on the PI substrate that forms during the initial stage of sputtering. We propose the introduction of an inorganic insulating underlayer at the interface between (Al,Ti)N and the PI substrate to prevent the formation of the amorphous phase. As a result, highly crystalline (Al,Ti)N was grown directly on an inorganic insulating underlayer and high heat resistance was achieved.