We investigate an alternative approach to conventional high dose ion-implanted photoresist strip and clean that replaces a remote plasma strip with a thermally activated, atmospheric gas-phase oxidation process and replaces sulfuric-peroxide mixture (SPM) chemistry with a de-ionized water/ozone (DIO_3) chemistry. The gas phase oxidation process is first characterized in a mini-test chamber. Then the alternative dry and wet clean sequence is entirely processed in a modified single-wafer wet clean chamber. The atmospheric dry O_3/O_2 gas mixture decomposes and reacts with the ion-implanted photoresist wafer that is heated above 300 °C from the backside. 9,000 A/min and 600 A/min removal rates are measured on 193 nm photoresist and high dose implanted crust, respectively. Silicon reactivity from ellipsometry measurements is lower than a typical remote oxygen plasma based on ～1 A silicon loss. The integrated process completely removes 5E15-1E 6 at/cm~2 high dose implanted 193 nm photoresist with no residue remaining on patterned substrates.
展开▼
