This application proposes a method for fabricating a MOS device. The method includes: performing
impurity doping on the source / drain regions of an initial
chip substrate to obtain a first
chip substrate; depositing a Ni sacrificial layer on the surface of the first
chip substrate to obtain a second chip substrate, wherein a portion of the Ni sacrificial layer deposited into vias diffuses into the
impurity-doped source / drain regions, forming a
nickel silicide layer on top of the
impurity-doped source / drain regions;
etching the Ni sacrificial layer of the second chip substrate to obtain a third chip substrate; depositing a contact
metal layer on the surface of the third chip substrate to obtain a fourth chip substrate; and heat-treating the fourth chip substrate to react the contact
metal layer with the
surface layer of the source / drain regions to form a
nickel-containing
metal silicide, thereby forming a MOS device. The technical solution of this application can improve the performance of MOS devices.