Browsing by Author "Chiang, Kuo-Chang"

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Characteristics of AgInSbTe-SiO(2) nanocomposite thin film applied to nonvolatile floating gate memory devices
(2010-10-22)
Chiang, Kuo-Chang
;
Hsieh, Tsung-Eong
;
材料科學與工程學系
;
Department of Materials Science and Engineering
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 degrees C annealing exhibited a distinct hysteresis memory window (Delta V(FB)) shift = 6.6 V and charge density = 5.2 x 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.
Characteristics of AgInSbTe-SiO2 nanocomposite thin film applied to nonvolatile floating gate memory devices
(2010-10-22)
Chiang, Kuo-Chang
;
Hsieh, Tsung-Eong
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Nanocomposite thin films containing AgInSbTe (AIST) particles embedded in an SiO2 matrix was prepared by sputtering deposition and its feasibility for nonvolatile floating gate memory (NFGM) was investigated. The sample subjected to a 400 degrees C annealing exhibited a distinct hysteresis memory window (Delta V-FB) shift = 6.6 V and charge density = 5.2 x 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 Sb2Te 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-SiO2 nanocomposite layer as the core structure of NFGM devices is able to simplify the device structure and fabrication process.
Effect of Nitrogen Incorporation to AgInSbTe-SiO(2) Nanocomposite Thin Films Applied to Nonvolatile Floating Gate Memory
(2011-03-01)
Chiang, Kuo-Chang
;
Hsieh, Tsung-Eong
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Nonvolatile floating gate memory devices containing AgInSbTe-SiO(2) nanocomposites as the charge trapping layers prepared by target-attached sputtering method at various nitrogen incorporation conditions were investigated. The nitrogen incorporation was found to be essential to the nonvolatile memory characteristics and a significant memory window (Delta V(FB)) shift = 6.9 V and charge density = 7.1 x 10(12) cm(-2) at +/- 8 V gate voltage sweep could be obtained in the sample with satisfied charge retention property. Transmission electron microscopy revealed the nanocomposite layers contain Sb(2) Te nanocrystals about 5 nm in diameter which may serve as the charge storage traps of memory devices. X-ray photoelectron spectroscopy indicated nitrogen incorporation may alleviate the oxidation of AIST phase and promote the reduction of antimony oxide to form metallic Sb(2) Te phase in nanocomposite layers, leading to the good nonvolatile memory characteristics of NFGM device containing the AIST-SiO(2) nanocomposite as the charge-storage trap layer.
Effect of Nitrogen Incorporation to AgInSbTe-SiO2 Nanocomposite Thin Films Applied to Nonvolatile Floating Gate Memory
(2011-03-01)
Chiang, Kuo-Chang
;
Hsieh, Tsung-Eong
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Nonvolatile floating gate memory devices containing AgInSbTe-SiO2 nanocomposites as the charge trapping layers prepared by target-attached sputtering method at various nitrogen incorporation conditions were investigated. The nitrogen incorporation was found to be essential to the nonvolatile memory characteristics and a significant memory window (Delta V-FB) shift = 6.9 V and charge density = 7.1 x 10(12) cm(-2) at +/- 8 V gate voltage sweep could be obtained in the sample with satisfied charge retention property. Transmission electron microscopy revealed the nanocomposite layers contain Sb-2 Te nanocrystals about 5 nm in diameter which may serve as the charge storage traps of memory devices. X-ray photoelectron spectroscopy indicated nitrogen incorporation may alleviate the oxidation of AIST phase and promote the reduction of antimony oxide to form metallic Sb-2 Te phase in nanocomposite layers, leading to the good nonvolatile memory characteristics of NFGM device containing the AIST-SiO2 nanocomposite as the charge-storage trap layer.
Effects of blocking oxide layer types on the performance of nonvolatile floating gate memory containing AgInSbTe-SiO2 nanocomposite thin films
(2017-01-01)
Chiang, Kuo-Chang
;
Hsieh, Tsung-Eong
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Influence of blocking oxide layer types on the performance of nonvolatile floating gate memory (NFGM) containing AgInSbTe (AIST)-SiO2 nanocomposite as the charge-trapping layer was investigated. In the NFGM containing a 7-nm thick SiO2 blocking oxide layer deposited by plasma-enhanced chemical vapor deposition (PECVD), a fairly large memory window (Delta V-FB) shift of 20.9 V with the charge density of 13 x 10(13) cm(-2) at +/- 15 V gate voltage sweep was achieved. As to the NFGM containing HfO2 blocking oxide layer, the device performance was inferior to that of PECVD-SiO2 device due to the diffusion of HfO2 into the nanocomposite layer. Interdiffusion resulted in the formation of HfSiOx phase and oxygen defects which might act as the leakage paths, consequently deteriorating the charge trapping efficiency of AIST nanocrystals (NCs) embedded in nanocomposite layer. Analytical results illustrated that the film quality and barrier height feature of blocking oxide layer are essential to form the deep trap sites in the programming layer to achieve a satisfactory NFGM performance with long-term reliability. (C) 2016 Elsevier B.V. All rights reserved.
Nonvolatile floating gate memory characteristics of Sb2Te-SiO2 nanocomposite thin films
(2013-02-01)
Yang, Cheng-Hsun
;
Chiang, Kuo-Chang
;
Hsieh, Tsung-Eong
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Nonvolatile floating gate memory (NFGM) device composed of Sb2Te nanocrystals (NCs) as the charge-storage traps embedded in SiO2 matrix was prepared by the target-attachment sputtering method at various nitrogen (N-2) incorporation conditions. Via post annealing at 450 degrees C in ambient air, the sample prepared at the condition N-2/Ar=0.1 exhibited a maximum memory window (Delta V-FB) shift=4.4 V and charge density=4.2x10(12) cm(-2) under +/- 7 V gate voltage sweep. N-2 incorporation not only reduced the Sb2Te NC size to about 5 nm, but also suppressed the oxygen defects and antimony oxides in the sample. Feasibility of the Sb2Te chalcogenide NCs to NFGM fabrication with the simplified process and relatively low annealing temperature is demonstrated. (C) 2012 Elsevier B.V. All rights reserved.
Nonvolatile floating gate memory containing AgInSbTe-SiO2 nanocomposite layer and capping the HfO2/SiO2 composite blocking oxide layer
(2012-06-08)
Chiang, Kuo-Chang
;
Hsieh, Tsung-Eong
;
材料科學與工程學系
;
Department of Materials Science and Engineering
An extremely large memory window shift of about 30.7 V and high charge storage density = 2.3 x 10(13) cm(-2) at +/- 23 V gate voltage sweep were achieved in the nonvolatile floating gate memory (NFGM) device containing the AgInSbTe (AIST)-SiO2 nanocomposite as the charge trap layer and HfO2/SiO2 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 degrees C was observed. In addition to inhibiting the Hf diffusion into the programming layer, incorporation of the SiO2 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-SiO2 nanocomposite layer in memory device fabrication with a simplified processing method and post-annealing at a comparatively low temperature of 400 degrees C in comparison with previous NC-based NFGM studies.