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/O-2 and NF3/He sources. A high efficiency NF3 in-situ cleaning recipe is demonstrated in diluting with diatomic gas, N-2. With lower first ionization energy and several dissociative electron attachment (DEA) reactions, the N-2 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/N-2 cleaning recipe offers 79.6% less PFC emission than C3F8 in-situ chamber clean.