1998 年 49 巻 6 号 p. 637-642
Polyimide film was studied as a resist for ceramic etching in condensed phosphoric acid. Resist films were formed with three different polyimide precursors developed as materials for passivation, insulation, or protective layers on LSIs. After etching alumina ceramic from 260°C to 320°C, we measured changes in resist thickness, resist film breakdown ratio, and etch factors. Resist film chemical resistance depended strongly on the type of polyimide precursor. Photosensitive polyimide, Photoneece UR-3140®, showed superior resistance to phosphoric acid at up to 320°C The etch factor was relatively low, around 1, however, regardless of resist film formation conditions, indicating that some further process, e. g., application of an adhesion promoter, was needed to enhance resist adhesion to substrates.