Memory characteristics of Au nanocrystals embedded in metal–oxide–semiconductor structure by using atomic-layer-deposited Al₂O₃as control oxide

Abstract

The nonvolatile memory characteristics of metal-oxide-semiconductor (MOS) structures containing Au nanocrystals in the Al 2 O 3 /SiO 2 matrix were studied. In this work, we have demonstrated that the use of Al 2 O 3 as control oxide prepared by atomic-layer-deposition enhances the erase speed of the MOS capacitors. A giant capacitance-voltage hysteresis loop and a very short erase time which is lower than 1 ms can be obtained. Compared with the conventional floating-gate electrically erasable programmable read-only memories, the erase speed was promoted drastically. In addition, very low leakage current and large turnaround voltage resulting from electrons or holes stored in the Au nanocrystals were found in the current-voltage relation of the MOS capacitors.

Study of tunneling mechanism of Au nanocrystals in HfAlO matrix as floating gate memory

“…2,3 Among the reported metals being studied as storage nodes, Au is chosen because of several reasons. 4,5 For instance, it is chemically more stable compared to other metals, yet the energy perturbation is smaller. 3 In addition, the relatively large work function of Au NCs makes a deep quantum well between the control oxide and tunnel oxide, which is desirable as the floating gate for charge trapping.…”

“…There has been a lot of work on the formation and electrical properties of Au NCs, 2,4,9 and there is also plenty of research on the write/erase mechanisms where Au NCs are used as floating gate memory nodes. 10,11 However, there is not much emphasis being put on comparing the experimental results of memory characterizations with the F-N tunneling mechanisms, and hence optimizing the formation of the Au NCs in the trilayer floating gate memory.…”

Impact of top electrode on electrical stress reliability of metal-insulator-metal capacitor with amorphous ZrTiO4 film

“…15 The cusps can be explained by the fact that the applied external field is fully compensated by the internal electric field built by the electrons trapped in the dielectric. 16 Given that the amount of traps in the dielectric of both types of capacitors is identical, for the sweeping from Ϫ3 V to +3 V, the cusp of the Al-electrode capacitors should appear at a larger absolute voltage since it has higher leakage current and therefore shorter sweeping time is enough to build the required internal field. However, those with Ni electrode display a larger absolute voltage for the cusp and thus there must exist additional different type͑s͒ of traps in the dielectric of the Al-electrode capacitors.…”

Effect of size and position of gold nanocrystals embedded in gate oxide of SiO2/Si MOS structures

“…1 Among the various species of metallic nanoparticles, gold (Au) has been reported to be chemically stable, be easily synthesized, and of high work function. 2 High work function of Au provides a high confinement barrier in the retention mode and a relatively low barrier in the programming and erasing modes. NCs are embedded between the layers of control oxide and tunneling oxide of a metal-oxide-semiconductor (MOS) structure.…”