The effect of electron stimulated desorption (ESD) during secondary ion mass spectrometry (SIMS) from BF+2 implanted SiO2 was investigated. We have quantitatively illustrated that the F+ depth profile is directly related to electron current density while the Si+ and B+ profiles remain nearly constant. We have also determined that ESD produces the same ionic species as does Ar+ bombardment. A mass analysis of ESD species from BF+2 implanted SiO2 has revealed a very extensive ionization from this surface. In addition to F+ , a significant abundance of Si+ , Si+2 , Si+3, and SiO+ ESD was also detected.