The effect of N2 flow rate in He/O2/N2 on the characteristics of large area pin-to-plate dielectric barrier discharge

In this study, the effects of N-2 flow rate in the He/O-2/N-2 gas mixture on the characteristics of a pin-to-plate dielectric barrier discharge (DBD) having the size of 100 mm x 1000 mm have been investigated for the application to flat panel display processing such as photoresist ashing. The pin-to-plate DBD showed about 70-120% higher photoresist ashing rate at the same applied voltage compared to the conventional DBD. The addition of 3 slm of N-2 to He(10slm)/O-2(3 slm) showed the highest photoresist ashing rate of about 580 nm/min for the pin-to-plate DBD at 12 kV of AC voltage. The increase of N2 flow rate in He/O-2 gas mixture up to 3 slm appeared to increase the density of N-2(+) ions and N-2 metastables while the oxygen atomic density appeared to decrease continuously. The increase of photoresist ashing rate with the increase of N-2 flow rate up to 3 slm was related to the increase of the substrate surface temperature by the increased collision of N-2(+) ions and N-2 metastables with the substrate.