Novel photoresist stripping technology using ozone/vaporized water mixture

The authors have developed a new process as an alternative to sulfuric peroxide mixture (SPM) cleaning of Si wafers. This process, vapor ozone strip (VOS), uses ozone and vaporized water, significantly reducing any effect on environment, health and safety. The process is more effective than ozone water immersion, because high concentration ozone gas and high temperature water can be used simultaneously. Also, the process uses the highly reactive OH* radical species. The VOS process is able to strip photoresist at a higher rate than other techniques using ozone. Ion implanted photoresist and etched photoresist can be stripped. VOS has demonstrated equivalent performance to SPM in electrical reliability testing.