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.

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An extremely large memory window shift of about 30.7 V and high charge storage density =2.3 × 10(13) cm(-2) at ± 23 V gate voltage sweep were achieved in the nonvolatile floating gate memory (NFGM) device containing the AgInSbTe (AIST)-SiO(2) nanocomposite as the charge trap layer and HfO(2)/SiO(2) as the blocking oxide layer. Due to the deep trap sites formed by high-density AIST nanocrystals (NCs) in the nanocomposite matrix and the high-barrier-height feature of the composite blocking oxide layer, a good retention property of the device with a charge loss of about 16.1% at ± 15 V gate voltage stress for 10(4) s at the test temperature of 85 °C was observed. In addition to inhibiting the Hf diffusion into the programming layer, incorporation of the SiO(2) layer prepared by plasma-enhanced chemical vapor deposition in the sample provided a good Coulomb blockade effect and allowed significant charge storage in AIST NCs. Analytical results demonstrated the feasibility of an AIST-SiO(2) nanocomposite layer in memory device fabrication with a simplified processing method and post-annealing at a comparatively low temperature of 400 °C in comparison with previous NC-based NFGM studies.

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Hydrogen (H 2 ) sensing property of AgInSbTe (AIST)-SiO 2 nanocomposite thin film prepared by target-attachment sputtering method was investigated in this work. The sample subjected to a 400°C-annealing for 90 sec exhibits a significant sensitivity (58.9 %) and short response time (75 sec) upon the exposure to an ambient containing 200 ppm H 2 at 75°C. The gas sensing capability is ascribed to the presence of antimony oxides, e.g., Sb 2 O 3 and Sb 2 O 5 , in nanocomposite layer which provide the charge carriers for sensing reactions. Moreover, the high specific-surface-area (SSA) feature of AIST nanocrystals in nanocomoposite layer provided numerous sites for reduction/oxidation reactions and thus a good H 2 gas sensing property can be achieved.

This work presents an enhancement of nonvolatile floating gate memory (NFGM) devices comprised of AgInSbTe (AIST) nanocomposite as the charge-storage trap layer and HfO 2 or HfO 2 /SiO 2 as the blocking oxide layer. A significantly large memory window (ΔV FB) shift = 30.7 V and storage charge density = 2.3×10 13 cm −2 at ±23V gate voltage sweep were achieved in HfO 2 /SiO 2 /AIST sample. Retention time analysis observed a ΔV FB shift about 19.3 V and the charge loss about 13.4% in such a sample under the ±15V gate voltage stress after 10 4 sec retention time test. Regardless of applied bias direction, the sample containing HfO 2 /SiO 2 layer exhibited the leakage current density as low as 150 nA/cm 2 as revealed by the current-voltage (I-V) measurement. This effectively suppresses the electron injection between gate electrode and charge trapping layer and leads to a substantial enhancement of NFGM characteristics.

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