Application of radiation-tolerant field oxides and passivation films to the bipolar IC process

By applying a double-layer oxide film as a field oxide, the radiation tolerance of n-p-n transistors is improved by one order of magnitude compared with conventional transistors. The buildup of interface states is affected by formation of passivation films, and interface-state buildup using the polymide resin PIQ is suppressed by one-fifth compared with that of inorganic passivation film. Even though irradiation temperature affects the buildup of the interface states, the current gain of an improved n-p-n transistor is sufficient to allow operation at 75 degrees C irradiation.<
>