Power dependence of NF3 plasma stability for in situ chamber cleaning

We investigated the stability of NF3 plasmas for in situ chamber cleaning in a production plasma-enhanced chemical vapor deposition reactor. An rf power threshold, normalized by NF3 molar number (Pnn) and NF3 flow rate (Pnf), is observed to be PnnPnf=39 (W/μ mol)(W/sccm) for stable plasmas with high NF3 destruction efficiency. This is rationalized by the energy required to maintain sufficient electron–ion pair creation in an electronegative discharge.