Abstract: Boron and Phosphorus doped oxides are important films in the processing of IC' s, both as a planarization dielectric and as a passivation. The accurate analysis of dopants in these films is also of great importance to the analytical chemist. In this paper, Boron and Phosphorus are determined by ICP-MS after the films dissolved by HF, HNO3. The errors of the results and those gotten by ICP-AES from Balazs Lab are less than 5%.