Utilizing embedded ultra-small Pt nanoparticles as charge trapping layer in flashristor memory cells

Abstract

In this study, a methodology for producing highly controlled and uniformly dispersed metal nanoparticles were developed by atomic layer deposition (ALD) technique. All-ALD grown thin film flash memory (TFFM) cells and their applications were demonstrated with ultra-small platinum nanoparticles (Pt-NPs) as charge trapping layer and control tunnel oxide layer. The ultra-small Pt-NPs possessed sizes ranging from 2.3 to 2.6 nm and particle densities of about 2.5 × 10 13 cm -b . The effect of Pt-NPs embedded on the storage layer for charging was investigated. The charging effect of ultra-small Pt-NPs the storage layer was observed using the electrical characteristics of TFFM. The Pt-NPs were observed by a high-resolution scanning electron microscopy (HR-SEM). The memory effect was manifested by hysteresis in the I DS -V DS and I DS -V GS curves. The charge storage capacity of the TFFM cells demonstrated that ALD-grown Pt-NPs in conjunction with ZnO layer can be considered as a promising candidate for memory devices. Moreover, ZnO TFFM showed a I ON /I OFF ratio of up to 52 orders of magnitude and its threshold voltage (V th ) was approximately −4.1 V using I ds −a/b -V gs curve. Fabricated TFFMs exhibited clear pinch-off and show n-type field effect transistor (FET) behavior. The role of atomic-scale controlled Pt-NPs for improvement of devices were also discussed and they indicated that ALD-grown Pt-NPs can be utilized in nanoscale electronic devices as alternative quantum dot structures.

Current Status on the Manufacturing of Nanomaterials for Proton Exchange Membrane Energy Systems by Vapor-Based Processes

“…In addition to the effect of the substrate, the specific precursor material chosen may also impact the ALD process . In many sources, trimethyl­(methylcyclopentadienyl) platinum­(IV) (MeCpPtMe 3 ) is the traditional precursor material for Pt ALD. − However, other literature sources have examined utilizing other Pt precursor materials such as platinum acetylacetonate . For this, it is important to account for the thermal stability of the precursor to obtain the desired result.…”

“…Traditional ALD uses oxygen gas to react with the organic ligand of the precursor material to leave the desired material on the substrate. − ,,, However, the use of oxygen typically requires a minimum operating temperature of 250 °C. Other researchers have used ozone as the reactant gas. ,,,,, The reactivity of ozone allows for the ALD process temperature to be reduced to around 100 °C while also functionalizing the surface of the substrate to improve nucleation . This allows for an increase in the growth rate when using ozone.…”

“…Other researchers have used ozone as the reactant gas. 98,102,105,107,108,111 The reactivity of ozone allows for the ALD process temperature to be reduced to around 100 °C while also functionalizing the surface of the substrate to improve nucleation. 98 This allows for an increase in the growth rate when using ozone.…”

Chemical and Structural Configuration of Pt-Doped Metal Oxide Thin Films Prepared by Atomic Layer Deposition

“…15 Recently, Orak et al have demonstrated the use of ALD for the successful deposition of ultrasmall Pt NPs, as a charge trapping layer in thin-film flash memory devices. 11 It is well known that the sensing ability of SMOs can be greatly enhanced by noble-metal doping. Pt-doped In 2 O 3 is one of the most interesting candidates among noble-metaldoped SMOs.…”

“…Among nanocrystal materials, metal NPs are considered highly promising because of a better lateral isolation of each storage site and high density of states . For charge storage in NVM devices, NPs such as Pt, Ag, and Au, embedded in dielectric layers, have been used, out of which Pt has been explored extensively. − In a metal-based single-electron transistor, the metal NPs are separated from the gate material by a thin layer of dielectric . In order to accomplish better device performance, an adequate fabrication method, which can precisely control the NPs’ size and surface areal density, as well as the dielectric thickness, is highly important.…”