Study of Polyimide Films as Passivation for High Temperature High Voltage Silicon Carbide Devices
Characterizations of Al/Polyimide/Al capacitors in a temperature range extended up to 400°C are presented. The aim is to determine the retained BPDA/PPD polyimide (PI) intrinsic dielectric and conduction properties, as a first stage in the evaluation of its ability to be applied as a passivation material for high temperature operating silicon carbide power devices. The dielectric constant, dielectric loss factor, and the static leakage current of the “as-prepared” Al/PI/Al structures are strongly affected above 175°C, reaching critical values at 400°C with regard to the aimed application. However, an evolution of these characteristics after the sample exposure at high temperature is observed, resulting in a very good and stabilized electrical behavior even at 400°C.
N. Wright, C.M. Johnson, K. Vassilevski, I. Nikitina and A. Horsfall
S. Diaham et al., "Study of Polyimide Films as Passivation for High Temperature High Voltage Silicon Carbide Devices", Materials Science Forum, Vols. 556-557, pp. 671-674, 2007