Methods of fabricating semiconductor devices are disclosed. An illustrated example method protects spacers and active areas by performing impurity ion implantation on an oxide layer prior to etching the oxide layer. The illustrated method includes forming a gate on a semiconductor substrate, forming a spacer on a sidewall of the gate, forming an oxide layer over the substrate, forming a mask on the oxide layer to cover a non-salicide area, implanting impurity ions into a portion of the oxide layer which is not covered by the mask, removing the portion of the oxide layer which is implanted with impurity ions, performing salicidation on the substrate, and removing the mask.