| 摘要 |
A method for fabricating a semiconductor device employs the way of first performing thermal annealing to the source/drain regions and then forming an ion-implanted region, such as a retrograde well. The method comprises the steps of: removing said dummy gate so as to expose said dummy gate dielectric layer and form an opening; performing ion implantation on the substrate from the opening to form an ion-implanted region; removing the dummy gate dielectric layer; performing thermal annealing to activate the dopants of the ion-implanted region; and depositing a new gate dielectric layer and a new metal gate in the opening in sequence, wherein the formed new gate dielectric layer covers the substrate and the inner walls of the sidewall spacers. By means of the present invention, it is possible to avoid inappropriately introducing the dopants of the ion-implanted region into the source region and the drain region, such that the profile of the ion-implanted region does not overlap with the dopants of the source/drain regions, thereby avoiding increasing the band-to-band leakage current in a MOSFET device. As a result, the performance of the device is improved. |
