Abstract: A method of fabricating an NMOS transistor, in which, an epitaxial silicon layer is formed before a salicide process is performed, then a nickel layer needed for the salicide process is formed, and, thereafter, a rapid thermal process is performed to allow the nickel layer to react with the epitaxial silicon layer and the silicon substrate under the epitaxial silicon layer to form a nickel silicide layer.

Abstract: An alignment mark for defect inspection is disclosed. The alignment mark includes: a semiconductor substrate; a first type well disposed in the semiconductor substrate; a second type doping region disposed in the first type well; a dielectric layer disposed on the semiconductor substrate to cover the first type well and the second type doping region; and a plurality of conductive plugs formed in the dielectric layer for connecting to the second type doping region.

Abstract: The method for in-line monitoring a wafer is described as follows. A wafer is provided, and at least one inspection structure is then formed on the wafer in the following steps. An N-well region and a P-well region are formed in the wafer, wherein the N-well region and the P-well region are separated from each other. A gate on each of the N-well region and the P-well region is formed. A P-type doped region is respectively formed in the N-well region and in the P-well region at both sides of the gates. A first contact plug is formed on each P-type doped region, and second contact plug is formed on each gate. Afterwards, a defect inspection is conducted utilizing an electron beam inspection (EBI) system, such that a short between each first contact plug and each gate is determined.

Abstract: A defect inspection method is disclosed. A first type defect inspection system is used to perform a first defect inspection by aligning to an alignment mark on a wafer as a reference point for the first defect inspection. A fabrication process is performed on the wafer thereafter, and a second defect inspection is performed by using a second type defect inspection system to align the alignment mark on the wafer as the reference point for the second defect inspection.

Abstract: A gate structure includes a gate disposed on a substrate, a first spacer disposed on the substrate and surrounding the gate and a second spacer disposed on the first spacer and surrounding the gate, the second spacer is lower than the first spacer.

Abstract: A defect inspection method is disclosed. A first type defect inspection system is used to perform a first defect inspection by aligning to an alignment mark on a wafer as a reference point for the first defect inspection. A fabrication process is performed on the wafer thereafter, and a second defect inspection is performed by using a second type defect inspection system to align the alignment mark on the wafer as the reference point for the second defect inspection.

Abstract: A method of fabricating a self-aligned contact is provided. A first dielectric layer is formed on a substrate having a contact region therein. Next, a lower hole corresponding to the contact region is formed in the first dielectric layer. Thereafter, a second dielectric layer is formed on the first dielectric layer, and then an upper hole self-aligned to and communicated with the lower hole is formed in the second dielectric layer, wherein the upper hole and the lower hole constitute a self-aligned contact hole. Afterwards, the self-aligned contact hole is filled with a conductive layer.