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Title: Impact of metal nano layer thickness on tunneling oxide and memory performance of core-shell iridium-oxide nanocrystals

Abstract

The impact of iridium-oxide (IrO{sub x}) nano layer thickness on the tunneling oxide and memory performance of IrO{sub x} metal nanocrystals in an n-Si/SiO{sub 2}/Al{sub 2}O{sub 3}/IrO{sub x}/Al{sub 2}O{sub 3}/IrO{sub x} structure has been investigated. A thinner (1.5 nm) IrO{sub x} nano layer has shown better memory performance than that of a thicker one (2.5 nm). Core-shell IrO{sub x} nanocrystals with a small average diameter of 2.4 nm and a high density of {approx}2 x 10{sup 12}/cm{sup 2} have been observed by scanning transmission electron microscopy. The IrO{sub x} nanocrystals are confirmed by x-ray photoelectron spectroscopy. A large memory window of 3.0 V at a sweeping gate voltage of {+-}5 V and 7.2 V at a sweeping gate voltage of {+-} 8 V has been observed for the 1.5 nm-thick IrO{sub x} nano layer memory capacitors with a small equivalent oxide thickness of 8 nm. The electrons and holes are trapped in the core and annular regions of the IrO{sub x} nanocrystals, respectively, which is explained by Gibbs free energy. High electron and hole-trapping densities are found to be 1.5 x 10{sup 13}/cm{sup 2} and 2 x 10{sup 13}/cm{sup 2}, respectively, due to the small size and high-density of IrO{submore » x} nanocrystals. Excellent program/erase endurance of >10{sup 6} cycles and good retention of 10{sup 4} s with a good memory window of >1.2 V under a small operation voltage of {+-} 5 V are obtained. A large memory size of >10 Tbit/sq. in. can be designed by using the IrO{sub x} nanocrystals. This study is not only important for the IrO{sub x} nanocrystal charge-trapping memory investigation but it will also help to design future metal nanocrystal flash memory.« less

Authors:
;  [1];  [2]; ;  [3]
  1. Thin Film Nano Tech. Lab., Department of Electronic Engineering, Chang Gung University, Tao-Yuan, Taiwan 333, Taiwan (China)
  2. Material Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan 310, Taiwan (China)
  3. Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China)
Publication Date:
OSTI Identifier:
22038735
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 110; Journal Issue: 7; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; ALUMINIUM OXIDES; FREE ENERGY; FREE ENTHALPY; HOLES; IRIDIUM OXIDES; LAYERS; NANOSTRUCTURES; PERFORMANCE; SILICON; SILICON OXIDES; TRANSMISSION ELECTRON MICROSCOPY; TRAPPING; TUNNEL EFFECT; X-RAY PHOTOELECTRON SPECTROSCOPY

Citation Formats

Banerjee, W., Maikap, S., Tien, T.-C., Li, W.-C., and Yang, J.-R. Impact of metal nano layer thickness on tunneling oxide and memory performance of core-shell iridium-oxide nanocrystals. United States: N. p., 2011. Web. doi:10.1063/1.3642961.
Banerjee, W., Maikap, S., Tien, T.-C., Li, W.-C., & Yang, J.-R. Impact of metal nano layer thickness on tunneling oxide and memory performance of core-shell iridium-oxide nanocrystals. United States. doi:10.1063/1.3642961.
Banerjee, W., Maikap, S., Tien, T.-C., Li, W.-C., and Yang, J.-R. Sat . "Impact of metal nano layer thickness on tunneling oxide and memory performance of core-shell iridium-oxide nanocrystals". United States. doi:10.1063/1.3642961.
@article{osti_22038735,
title = {Impact of metal nano layer thickness on tunneling oxide and memory performance of core-shell iridium-oxide nanocrystals},
author = {Banerjee, W. and Maikap, S. and Tien, T.-C. and Li, W.-C. and Yang, J.-R.},
abstractNote = {The impact of iridium-oxide (IrO{sub x}) nano layer thickness on the tunneling oxide and memory performance of IrO{sub x} metal nanocrystals in an n-Si/SiO{sub 2}/Al{sub 2}O{sub 3}/IrO{sub x}/Al{sub 2}O{sub 3}/IrO{sub x} structure has been investigated. A thinner (1.5 nm) IrO{sub x} nano layer has shown better memory performance than that of a thicker one (2.5 nm). Core-shell IrO{sub x} nanocrystals with a small average diameter of 2.4 nm and a high density of {approx}2 x 10{sup 12}/cm{sup 2} have been observed by scanning transmission electron microscopy. The IrO{sub x} nanocrystals are confirmed by x-ray photoelectron spectroscopy. A large memory window of 3.0 V at a sweeping gate voltage of {+-}5 V and 7.2 V at a sweeping gate voltage of {+-} 8 V has been observed for the 1.5 nm-thick IrO{sub x} nano layer memory capacitors with a small equivalent oxide thickness of 8 nm. The electrons and holes are trapped in the core and annular regions of the IrO{sub x} nanocrystals, respectively, which is explained by Gibbs free energy. High electron and hole-trapping densities are found to be 1.5 x 10{sup 13}/cm{sup 2} and 2 x 10{sup 13}/cm{sup 2}, respectively, due to the small size and high-density of IrO{sub x} nanocrystals. Excellent program/erase endurance of >10{sup 6} cycles and good retention of 10{sup 4} s with a good memory window of >1.2 V under a small operation voltage of {+-} 5 V are obtained. A large memory size of >10 Tbit/sq. in. can be designed by using the IrO{sub x} nanocrystals. This study is not only important for the IrO{sub x} nanocrystal charge-trapping memory investigation but it will also help to design future metal nanocrystal flash memory.},
doi = {10.1063/1.3642961},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 7,
volume = 110,
place = {United States},
year = {2011},
month = {10}
}