Efficient fabrication and characterization of cobalt nanoparticles embedded in metal∕oxide∕semiconductor structures for the application of nonvolatile memory

Abstract

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 5nm in diameter were clearly embedded in SiO2 layer. Capacitance-voltage measurements of Pt∕SiO2∕Co NPs∕SiO2 on p-type Si (100) substrate certainly exhibited typical MOS behavior with a flatband voltage shift of 1.1V. 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.

High density Ru nanocrystal deposition for nonvolatile memory applications

“…The nanocrystals are fully charged at a control gate voltage of 7 V for 30 s, and the subsequent charge loss is measured at a constant bias of 1 V. Charge loss of the continuous nanocrystal array after 1000 s of stress time is 2%, which suggests good retention properties, and is similar to the loss rate of other nanocrystal memory devices. 2,26,27 Phosphoric acid is then used to selectively etch the Al 2 O 3 and embedded nanocrystals bordering the control gate area. This produces a confined configuration, where the nanocrystal array in the region underneath the gate is isolated from neighboring nanocrystals outside this region.…”