Remote plasma sources sustained in NF3 mixtures

Remote plasma sources (RPS) are being developed for low damage materials processing during semiconductor fabrication. Plasmas sustained in NF3 are often used as a source of F atoms. NF3 containing gas mixtures (e.g., NF3/O2, NF3/H2) provide the additional opportunity to produce and control desirable F atom containing reactive species. In this paper, results from computational investigations of RPS are discussed using global and multidimensional models. A comprehensive reaction mechanism for plasmas sustained in Ar/NF3/N2/H2/O2 was developed using ab initio cross sections for NFx based on the molecular R-matrix method. NFx rapidly dissociates due to dissociative attachment. Addition of O2 enables formation of NO, FO and FNO from the dissociation products.