The invention discloses a
semiconductor structure and a forming method thereof. The forming method comprises the following steps of: forming a first through hole that penetrates through a
dielectric layer and exposes a surface of a source-drain
doping region; forming a second through hole that penetrates through the
dielectric layer and exposes a top of a gate structure; depositing cap
layers on abottom and sidewalls of the first through hole and a bottom and sidewalls of the second through hole; performing a first cleaning process on the bottom of the first through hole and the bottom of thesecond through hole to remove cap
layers located on the bottom of the first through hole and the bottom of the second through hole; performing a second cleaning process on the source-drain
doping region exposed at the bottom of the first through hole and the gate structure exposed at the bottom of the second through hole after the first cleaning process; forming
metal layers on the bottom and thesidewalls of the first through hole, the bottom and the sidewalls of the second through hole and a top of the
dielectric layer after the second cleaning process; and performing an annealing process on the
metal layers to convert the
metal layer located on the source-drain
doping region into a
metal silicide layer. According to the invention, the electrical properties of the formed
semiconductor structure can be improved.