抄録
We propose an effective and environmentally friendly dry stripping method using a supercritical carbon dioxide (SCCO2) system modified by a single or multiple cosolvents to remove ion-implanted photoresist and residue from a wafer surface at temperatures from 40°C to 100°C and pressures from 90 bar to 340 bar. After high dose of ion implantation the photoresist was not easily removed by using pure SCCO2. Therefore, a polar solvent was added as a cosolvent that is highly soluble in SCCO2 to remove heavy organics (photoresist and photoresist residue). The SCCO2 system modified by a single cosolvent could not effectively remove, but swell the heavy organics. However, the SCCO2 system modified by multiple cosolvents showed a high removal efficiency of ion-implanted photoresist (about 95%). In this study it has been shown that the dry stripping method using a SCCO2 system modified by multiple cosolvents can replace the plasma ashing or acid and solvent wet bench methods and dramatically reduce associated chemical usage and disposal.
