A method for restricting lateral encroachment of the metal silicide into the channel region, comprising: providing a semiconductor substrate, a gate stack being formed on the semiconductor substrate, a source region being formed in the semiconductor on one side of the gate stack, and a drain region being formed in the semiconductor substrate on the other side of the gate stack; forming a sacrificial spacer around the gate stack and on the semiconductor substrate; depositing a metal layer for covering the semiconductor substrate, the gate stack and the sacrificial spacer; performing a thermal treatment on the semiconductor substrate, thereby causing the metal layer to react with the sacrificial spacer and the semiconductor substrate in the source region and the drain region; removing the sacrificial spacer, reaction products of the sacrificial spacer and the metal layer, and a part of the metal layer which does not react with the sacrificial spacer.