Characteristics of AgInSbTe–SiO₂nanocomposite thin film applied to nonvolatile floating gate memory devices

Abstract

Nanocomposite thin films containing AgInSbTe (AIST) particles embedded in an SiO(2) matrix was prepared by sputtering deposition and its feasibility for nonvolatile floating gate memory (NFGM) was investigated. The sample subjected to a 400 °C annealing exhibited a distinct hysteresis memory window (ΔV(FB)) shift = 6.6 V and charge density = 5.2 × 10(12) cm(-2) after ± 8 V gate voltage sweep. Electrical measurement revealed the current transport is via the Schottky emission in low applied field and the space-charge-limited conduction mechanism in high applied field in the samples, regardless of their thermal history. Transmission electron microscopy and x-ray photoelectron spectroscopy indicated that the metallic Sb(2)Te nanocrystals (NCs) with diameters about 5-7 nm dispersed in a nanocomposite layer may serve as the discrete charge-storage traps for nonvolatile memory. Analytical results illustrate the utilization of an AIST-SiO(2) nanocomposite layer as the core structure of NFGM devices is able to simplify the device structure and fabrication process.

Preparation of activated carbon from spent catalyst with mercury by microwave‐induced CO2 activation

“…With the increase of temperature, the unsaturated organic groups with oxygen of regenerated substrate decreased. At 900°C, the binding of either and aldehyde showed significant enhancement, which is also consistent with the FI‐IR results . The peaks at 289.1 eV can be assigned to CO 3 2− , which would combine with Ba 2 + and Ca 2+ .…”

“…At 900°C, the binding of either and aldehyde showed significant enhancement, which is also consistent with the FI-IR results. 35,36 The peaks at 289.1 eV can be assigned to CO 3 2− , which would combine with Ba 2 + and Ca 2+ . It is worth mentioning that the molecular weight percentage of CO 3 2− shows the tendency of an initial increase and subsequent decrease.…”

Nonvolatile floating gate memory containing AgInSbTe–SiO2nanocomposite layer and capping the HfO2/SiO2composite blocking oxide layer

“…The maximum charge storage density was found to be 2.3 × 10 13 cm −2 according to the formula [23], N = (C acc V FB )/(qA), where C acc is the accumulation capacitance, q is the electron charge and A is the electrode area. In comparison with the C-V properties of NFGM containing a sole AIST-SiO 2 nanocomposite layer [26], the capping of the HfO 2 /SiO 2 composite blocking oxide layer indeed improved the electrical performance of the NFGM device.…”

“…Moreover, chalcogenides possess the E g and electron affinities similar to those of Si and their charge trapping effects are suitable for NFGM applications [25]. The feasibility of chalcogenides to NFGM has been demonstrated by the study which reports the V FB shift = 6.6 V at ±8 V gate voltage sweep and charge storage density = 5.2 × 10 12 cm −2 in the device containing a sole AgInSbTe (AIST)-SiO 2 nanocomposite programming layer [26]. In this study, the AIST-SiO 2 nanocomposite-based NFGM capped by the HfO 2 /SiO 2 composite blocking oxide layer is prepared and the correlations of electrical performance to microstructures of such a memory device are evaluated accordingly.…”

“…After mounting an appropriate number of AIST pellets on a 3 inch quartz sputtering target, the deposition of the AIST-SiO 2 nanocomposite layer was carried out in a vacuum system with background pressure better than 2 × 10 −6 Torr. About a 30 nm thick AIST-SiO 2 nanocomposite layer was deposited on the Si substrate via the target-attachment sputtering method [26,27] under the conditions of working pressure = 3 mTorr, rf gun power = 100 W and argon (Ar)/N 2 inlet gas flow ratio = 10:2 (in units of sccm). The purpose of N 2 incorporation during sputtering is to suppress the oxygen defects in the nanocomposite layer [28] and enhance the surface polarization effect [29] so as to improve the leakage current property.…”