Effect of fluorine on chemical and electrical properties of room temperature oxide films prepared by plasma enhanced chemical vapor deposition

The effect of fluorine on SiO2 films was investigated by comparing chemical and electrical properties of fluorinated silicon oxide (SIOF) films with those of SiO2 films. The SIOF films were prepared at room temperature by plasma enhanced chemical vapor deposition incorporating CF4 as the fluorine source into the deposition process of the SiO2 films using Si2H6 and N2O. The relative dielectric constant of the as-deposited SiO2 films was reduced from 5.95 to 4.43 by the incorporation of fluorine and with postmetallization anneal. The breakdown measurements on the SiOF films showed no early failures at a field strength of less than or equal to 3 MV/cm, resulting in an average breakdown field strength of 7.11 MV/cm. (C) 1998 American Institute of Physics. [S0003-6951(98)01710-0].