Silicon Oxide Etching Process of NF(3) and F(3)NO Plasmas with a Residual Gas Analyzer

The use of NF(3) is significantly increasing every year. However, NF(3) is a greenhouse gas with a very high global warming potential. Therefore, the development of a material to replace NF(3) is required. F(3)NO is considered a potential replacement to NF(3). In this study, the characteristics and cleaning performance of the F(3)NO plasma to replace the greenhouse gas NF(3) were examined. Etching of SiO(2) thin films was performed, the DC offset of the plasma of both gases (i.e., NF(3) and F(3)NO) was analyzed, and a residual gas analysis was performed. Based on the analysis results, the characteristics of the F(3)NO plasma were studied, and the SiO(2) etch rates of the NF(3) and F(3)NO plasmas were compared. The results show that the etch rates of the two gases have a difference of 95% on average, and therefore, the cleaning performance of the F(3)NO plasma was demonstrated, and the potential benefit of replacing NF(3) with F(3)NO was confirmed.