Synthesis and memory effect study of Ge nanocrystals embedded in LaAlO3 high-k dielectrics

Lu, X. B.; Lee, P. F.; Dai, J. Y.
May 2005
Applied Physics Letters;5/16/2005, Vol. 86 Issue 20, p203111
Academic Journal
A floating gate memory structure utilizing Ge nanocrystals embedded in LaAlO3 (LAO) high-k dielectric films has been fabricated by pulsed-laser deposition. A cross-sectional high-resolution transmission electron microscopy study revealed that the floating gate structure contains 5-nm-diam spherelike Ge nanocrystals embedded in amorphous LAO. A significant memory effect with a very high density of charge storage up to 2×1013/cm2 in the Ge nanocrystals and a maximum flat band voltage shift of 3.2 V have been achieved for the trilayer structure of LAO(8 nm)/Ge/LAO(3 nm)/Si. The memory structure utilizing the Ge nanocrystals grown in 1 min showed excellent charge retention characteristics, whereas the decay in memory capacitance after 104 s of stress under a flat band voltage was only 8%. These results suggest that this memory structure utilizing Ge nanocrystals embedded in a LAO dielectric offers a high potential for the further scaling of floating gate memory devices. In addition, the effects of Ge growth time, and thus the size and density of the Ge nanocrystals, to the charge storage and charge retention characteristics were also studied.


Related Articles

  • Pd-nanocrystal-based nonvolatile memory structures with asymmetric SiO2/HfO2 tunnel barrier. Seol, Kwang Soo; Choi, Seong Jae; Choi, Jae-Young; Jang, Eun-Joo; Kim, Byung-Ki; Park, Sang-Jin; Cha, Dea-Gil; Song, In-Yong; Park, Jong-Bong; Park, Youngsoo; Choi, Suk-Ho // Applied Physics Letters;8/21/2006, Vol. 89 Issue 8, p083109 

    Pd nanocrystals (NCs) on asymmetric tunnel barrier (ATB) composed of stacked SiO2 and HfO2 layers have been employed for nonvolatile memory devices. The Pd-NC layers are formed by electrostatic self-assembly of negatively charged colloidal Pd NCs. The presence of isolated Pd NCs of ∼5 nm...

  • Study of charge distribution and charge loss in dual-layer metal-nanocrystal-embedded high-κ/SiO2 gate stack. Lwin, Z. Z.; Pey, K. L.; Zhang, Q.; Bosman, M.; Liu, Q.; Gan, C. L.; Singh, P. K.; Mahapatra, S. // Applied Physics Letters;5/7/2012, Vol. 100 Issue 19, p193109 

    In this work, we present a comprehensive experimental study of charge loss mechanisms in a dual-layer metal nanocrystal (DL-MNC) embedded high-κ/SiO2 gate stack. Kelvin force microscopy characterization reveals that the internal-electric-field assisted tunneling could be a dominant charge...

  • Ge nanocrystals formation on SiO2by dewetting: application to memory. P. Szkutnik; A. Karmous; F. Bassani; A. Ronda; I. Berbezier; K. Gacem; A. El Hdiy; M. Troyon // European Physical Journal - Applied Physics;Feb2008, Vol. 41 Issue 2, p103 

    Ge nanocrystals (NCs) are produced by a dewetting process during annealing of an amorphous Ge layer deposited on an ultra thin SiO2layer. We have investigated the characteristics of the resulting NCs as a function of the nominal Ge layer thickness. Thanks to transmission electron microscopy...

  • Texturization of polycrystalline silicon films using excimer-laser processing for memory device.... Yu, C.; Mathews, V.K. // Applied Physics Letters;3/23/1992, Vol. 60 Issue 12, p1501 

    Investigates a technique for texturizing polycrystalline silicon films using excimer laser processing for memory device applications. Sensitivity of the degree of texturization to both film-deposition and laser fluence; Use of polycrystalline silicon film as capacitor-storage node; Analysis of...

  • Scientists say organic non-volatile memory is fastest and cheapest. Ball, Richard // Electronics Weekly;6/26/2002, Issue 2058, p1 

    Reports on the development of an organic, non-volatile memory device by a team led by associate professor Yang Yang at the School of Engineering of the University of California in Los Angeles. Features and mechanism of the device; Causes of the disappearance of the bistability phenomenon in the...

  • Scandium oxide deposited by high-pressure sputtering for memory devices: Physical and interfacial properties. Feijoo, P. C.; del Prado, A.; Toledano-Luque, M.; San Andrés, E.; Lucía, M. L. // Journal of Applied Physics;Apr2010, Vol. 107 Issue 8, p084505 

    Scandium oxide (ScOx) thin layers are deposited by high-pressure sputtering (HPS) for physical and electrical characterization. Different substrates are used for comparison of several ScOx/Si interfaces. These substrates are chemical silicon oxide (SiOx), H-terminated silicon surface and silicon...

  • High-performance and room-temperature-processed nanofloating gate memory devices based on top-gate transparent thin-film transistors. Il-Suk Kang; Young-Su Kim; Hyun-Sang Seo; Se Wan Son; Eun Ae Yoon; Seung-Ki Joo; Chi Won Ahn // Applied Physics Letters;5/23/2011, Vol. 98 Issue 21, p212102 

    Transparent nanofloating gate memory devices based on top-gate zinc oxide thin-film transistors were developed. The proposed devices contained a facile and dry-synthesized palladium nanocluster array as a charge-trapping layer. The good programmable memory characteristics were exhibited due to...

  • Digital thin-film color optical memory. Chi, C. J.; Steckl, A. J. // Applied Physics Letters;1/8/2001, Vol. 78 Issue 2, p255 

    A promising optical memory device called digital thin-film (DTF) color optical memory is presented. The DTF optical memory utilizes localized regions of varying thickness to adjust the spectral characteristic of reflected light from a broad band source. The DTF structure has been fabricated by...

  • Highly thermally stable TiN nanocrystals as charge trapping sites for nonvolatile memory device applications. Choi, Sangmoo; Kim, Seok-Soon; Chang, Man; Hwang, Hyunsang; Jeon, Sanghun; Kim, Chungwoo // Applied Physics Letters;3/21/2005, Vol. 86 Issue 12, p123110 

    TiN nanocrystals formed by a co-sputtering method have been investigated as discrete charge traps for metal–oxide–nitride–oxide–silicon-type nonvolatile memory devices. The formation of isolated TiN nanocrystals embedded in Al2O3 was confirmed by transmission electron...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics