Investigation of molybdenum contamination in /sup 11/B/sup +/ and /sup 31/P+ implants

Ion implantation ion source equipment employing Mo or W arc chambers, W filaments and Al/sub 2/O/sub 3/ insulators allow F from BF/sub 3/ source gasses to chemically react, forming metallic fluorides and oxides that are volatile species at common operating temperatures. These gases get ionized and extracted together with the desired ions. There is evidence that all MoF/sub x/ molecules (1