Fig. 6 | Scientific Reports

Fig. 6

From: Effect of C2H2F4/CF4O with low global warming potentials on SiNx etching as a CHF3 replacement

Fig. 6

Schematic drawings of etch mechanism for SiOx masked SiNx etching with CHF3, C2H2F4, C2H2F4+CF4O-based gases. (a) for CHF3-based gas, due to the SiNx oxidation, the etching of SiNx is very slow. (b) for C2H2F4-based gas, due to the polymer formation, trenching is formed at the SiNx pattern bottom edge. (c) for C2H2F4+CF4O, the polymer layer in the pattern is effectively removed and highly anisotropic SiNx etching is obtained.

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