The slope etching technology of hydrogenated amorphous silicon film (a-Si:H) has been very useful for its devices; thin film transistor, contact image sensor and other large area electronic components. To obtain a good step coverage slope etching was performed by RIE using CF4 gas and optimum amount of O2 gas after modification of photoresist(PR) patterns by thermal treatment. In this experiment, primary factors were
1) thermal treatment temperature and time of PR.
2) CF4 gas flow rate, etch rate of a-Si:H film and ash rate of PR in proportion to O2 gas flow rate.
As a result, the slope angle of 11° was obtained when CF4 gas flow rate was 46 SCCM, O2 gas flow rate was 7 SCCM and thermal treatment temperature and time was 140°C and 30 minutes respectively.