Post Plasma Etch Residue Removal Using CO[sub 2]-TMAHCO[sub 3] Mixtures: Comparison of Single-Phase and Two-Phase Mixtures

Photoresist and post etch residue removal were studied as functions of the cleaning-mixture-phase state. Solutions of tetramethylammonium bicarbonate in methanol were used as cosolvents with The phase behavior of this mixture was studied at temperatures between 25 and 70°C and mole ratios of 0.127 and 0.02. At a cosolvent flow rate of 0.0262 mol/h, the single-phase mixture was more efficient for photoresist and etch residue removal than the two-phase mixture. Blanket plasma deposited fluorocarbon films were used to investigate the removal mechanism. The removal process was reaction rate limited and depended on the temperature and active species concentrations. This novel cleaning mixture displayed minimal reaction with and Coral™ films.