Water-Erasable Memory Device for Security Applications Prepared by the Atomic Layer Deposition of GeO₂

Abstract

We have investigated the atomic layer deposition (ALD) of GeO2 thin films that dissolve in water rapidly and have excellent electrical properties for use in memory devices. The growth characteristics based on surface reactions during the ALD process are discussed by correlation with experimental results and atomistic theoretical calculation. Compared to sputtered GeO2 films, the ALD-grown GeO2 is perfect, pure, and water-soluble at room temperature and has better electrical properties for use as the dielectric layer in memory devices. The superior film properties of ALD GeO2 are attributed to the higher film density, high purity, low roughness, and highly stoichiometric film composition. Finally, we demonstrate the fabrication of charge-trapping memory (CTM) devices with ALD GeO2, and that the electrical information stored in the CTM can be eliminated immediately by exposure to one droplet of water at room temperature. Thus, ALD GeO2 could find widespread application in the fabrication of secure memory devices.

Sn1–xGexOy and Zn1–xGexOy by Atomic Layer Deposition─Growth Dynamics, Film Properties, and Compositional Tuning for Charge Selective Transport in (Ag,Cu)(In,Ga)Se2 Solar Cells

“…Based on this interruption experiment and the general trends in GPC and MPC for the ZGO process, we speculate that exposing the GeO y surface to DEZ poisons a significant amount of s*-Ge–OH reaction sites by binding C 2 H 5 directly to Ge. We further speculate that the direct bond between Ge and C 2 H 5 is strong enough to prevent its reaction with H 2 O in subsequent cycles at this deposition temperature of 120 °C, which is relatively low compared to previously published ALD GeO y processes. − The implication of this for the ZGO supercycle processes would be that the more the GeO y cycles used in a row, the more the Ge–OH on the surface and the more the reaction sites end up being poisoned during the DEZ exposure. As a result, the GPC would decrease as the amount of GeO y cycles in the ZGO supercycle increases.…”

Elucidating the Reaction Mechanism of Atomic Layer Deposition of Al2O3 with a Series of Al(CH3)xCl3–x and Al(CyH2y+1)3 Precursors

“…The Hf­(N­(CH 3 ) 2 ) 4 precursor, in turn, led to deposited HfO 2 films with a reduced amount of suboxides and better electrical performance compared to HfCl 4 . Similarly, a dependence of deposited film properties on the choice of ALD precursors has been found in other ALD systems as well, such as HfO 2 , ZrO 2 , TiO 2 , GeO 2 , SiO 2 , TiN, TaN, Ru, Cu, and Pt …”

Germanium‐based monoelemental and binary two‐dimensional materials: Theoretical and experimental investigations and promising applications

“…GeO 2 nanosheets and films, even one atomic layer GeO 2 structure, have been synthesized in amorphous and crystalline 2D forms for many years. [297][298][299][300][301][302][303][304][305][306][307] However, GeO 2 materials do not include any vdW layered bulk materials; this is different from the common situation in which the 2D structures are usually simple monolayers of the bulk.…”