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

A green cleaning method involving oxidative degradation in supercritical carbon dioxide (scCO(2)) 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 scCO(2). Surface characterization and microscopic examination were conducted to investigate the polymer residue. The results indicate that oxidative degradation by benzoyl peroxide in scCO(2) provides an effective alternative route to remove post-RIE polymer residue in semiconductor devices.