Metal-oxide-semiconductor (MOS) capacitors with Co nanoparticles (Co NPs) were successfully fabricated by utilizing an external laser irradiation method for the application of nonvolatile memory. Experimental images of cross-sectional transmission electron microscopy showed that the Co NPs of 5 nm in diameter were clearly embedded in SiO2 layer. Capacitance-voltage measurements of Pt/SiO2/Co NPs/SO2 on p-type Si (100) substrate certainly exhibited typical MOS behavior with a flatband voltage shift of 1.1 V. In addition, the charge retention characteristics of MOS capacitors with the Co NP were investigated using Capacitance-time measurements. The present results indicate that their unique laser process gives rise to a possible promise for the efficient formation or insertion of metal NPs inside the MOS structures. (c) 2006 American Vacuum Society.