Surface Temperature Increase in Reactive Ion Beam Etch and Improvement of Profiles by Multistep Etching

We have carried out an in-situ measurement of temperature variation by a radiation thermometer during Cl2-reactive ion beam etch (RIBE). It is found that the surface temperature of the sample is noticeably increased by the etching with high ion-extraction voltage. The surface temperature was increased by about 250 K under ion irradiation with extraction voltage of 400 V for 15 min. We found that side-etch is caused by the temperature rise of the sample surface due to ion irradiation. We have also proposed a multistep RIBE for improving etched profiles.