Stillinger-Weber (SW)-type potential sets have been developed for Si-O-F and Si-O-Cl systems based on interatomic potential energy data obtained from ab initio quantum-mechanical calculations. We have constructed the new potential sets in such a way that the obtained potentials are supersets of existing well-known SW-type potentials for Si, SiO2, and Si-halogen systems. Our aim of the potential development is to perform molecular dynamics (MD) simulations for both silicon and silicon dioxide etching by F or Cl on the same footing. Presented in this article are details of the potential derivation and some sample MD simulation results.