The N2 diluted Application in PECVD NF3 in-situ chamber cleaning for PFC reduction

For plasma enhanced chemical vapor deposition (PECVD) chamber cleaning, the in-situ plasma cleaning method was widely used with C₃F₈/N₂O/O₂ and NF₃/He sources. A high efficiency NF₃ in-situ cleaning recipe is demonstrated in diluting with diatomic gas, N₂. With lower first ionization energy and several dissociative electron attachment (DEA) reactions, the N₂ is characterized as catalyst and increase the dissociation of NF₃. The cleaning uniformity problem is also solved by statistical design of experiment (DOE) approach; the well-optimized NF₃/N₂ cleaning recipe offers 79.6% less PFC emission than C3F8 in-situ chamber clean.