Study on O₂ reactive ion etching technology of EPG 535 photoresist

EPG 535 photoresist and CdZnTe substrate were etched respectively by means of O₂ reactive ion etching (RIE) technique. The surface roughness of CdZnTe substrate were detected by atomic force microscope (AFM). The effects of RF power, O₂ pressure and the flux of O₂ rate on etching rate of EPG 535 photoresist and the surface roughness of CdZnTe substrate were explored. The results showed that the etching rate was up to extremum when RF power was 60 W, O₂ pressure was 1.30 Pa and the flux of O₂ was 40 cm³/min. Surface roughness of CZT substrate after etching decreased with decreasing of RF power. The optimized RIE parameters were as follows: RF power 40 W; O₂ pressure 1.30 Pa and the flux of O₂ 40 cm³/min.