HEAT-PROOF PROPERTIES OF TA2N ANODIZED THIN-FILM CAPACITORS PREPARED AT LOW ANODIZATION VOLTAGE

To clarify how the high heat-proof properties of Ta2N anodized film ca pacitors are maintained when the film thickness is reduced, the effect s of heat treatment temperature increase on dissipation factor (tan de lta), temperature coefficient of capacitance and de leakage current ar e studied for a capacitor formed by reducing the anodization voltage. The results will follow. Even for the anodized capacitor prepared at a reduced anodization voltage of 80 V, there is no thermal degradation in tan delta and temperature coefficient of capacitance for the heat t reatment below 400 degrees C. The leakage current also shows a qualita tively similar behavior for a reduced anodization voltage with no chan ge in the electrical conduction mechanism, even when the anodization v oltage is reduced. On the other hand, while the leakage current of thi s Ta2N anodized film formed at 80 V changes little up to a heat-treatm ent temperature of 300 degrees C, it increases rapidly at 350 degrees C. However, compared to a Ta anodized film formed at 160 V anodization voltage with the same capacitance, this Ta2N anodized film formed at 80 V has a drastically improved heat resistance in terms of tan delta, temperature coefficient of capacitance and leakage current. From thes e results, it has been clarified that the use of Ta2N compound is an e xtremely effective way to maintain heat resistance while reducing the film thickness.