A method for forming a semiconductor structure is provided. The method includes forming a gate structure over a fin structure, forming a source/drain structure in the fin structure and adjacent to the gate structure, forming a dielectric layer over the gate structure and the source/drain structure, and forming an opening in the dielectric layer to expose the source/drain structure. The method further includes depositing a barrier layer lining a sidewall surface of the opening and a top surface of the source/drain structure. The method further includes etching a portion of the barrier layer to expose the source/drain structure. The method further includes depositing a glue layer covering the sidewall surface of the opening and the source/drain structure in the opening. The method further includes forming a contact structure filling the opening in the dielectric layer. The contact structure is surrounded by the glue layer.