Supercritical carbon dioxide-assisted oxidative degradation and removal of polymer residue after reactive ion etching of photoresist

Abstract

A green cleaning method involving oxidative degradation in supercritical carbon dioxide (scCO₂) to remove the polymer residue from chlorine reactive ion etching (RIE) and ashing of photoresist was developed. Benzoyl peroxide dissolved in pentane-2,4-dione was used as an oxidizing reagent to degrade the polymer residue. Random chain scission products from oxidative degradation were removed by scCO₂. Surface characterization and microscopic examination were conducted to investigate the polymer residue. The results indicate that oxidative degradation by benzoyl peroxide in scCO₂ provides an effective alternative route to remove post-RIE polymer residue in semiconductor devices.