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Microstructural, chemical bonding, stress development and charge storage characteristics of Ge nanocrystals embedded in hafnium oxide

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Abstract

We have grown Ge nanocrystals (NCs) (4.0–9.0 nm in diameter) embedded in high-k HfO2 matrix for applications in floating gate memory devices. X-ray photoelectron spectroscopy has been used to probe the local chemical bonding of Ge NCs. The analysis of Ge–Ge phonon vibration using Raman spectroscopy has shown the formation of compressively stressed Ge NCs in HfO2 matrix. Frequency dependent electrical properties of HfO2/Ge-NCs in HfO2/HfO2 sandwich structures have been studied. An anticlockwise hysteresis in the capacitance–voltage characteristics suggests electron injection and trapping in embedded Ge NCs. The role of interface states and deep traps in the devices has been thoroughly examined and has been shown to be negligible on the overall device performance.

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Acknowledgments

This work was supported in part by sponsored research grant from DRDO FIR and DST MBE projects. One of the authors (S. Das) acknowledges the Council of Scientific and Industrial Research, Government of India, for awarding fellowship to carry out this work.

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Authors and Affiliations

  1. Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India

    S. Das, R. K. Singha, S. Manna, A. Dhar & S. K. Ray

  2. School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK

    S. Gangopadhyay

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  1. S. Das
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  2. R. K. Singha
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  3. S. Manna
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  4. S. Gangopadhyay
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  5. A. Dhar
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Correspondence to S. K. Ray.

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Das, S., Singha, R.K., Manna, S. et al. Microstructural, chemical bonding, stress development and charge storage characteristics of Ge nanocrystals embedded in hafnium oxide. J Nanopart Res 13, 587–595 (2011). https://doi.org/10.1007/s11051-010-0054-8

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  • DOI: https://doi.org/10.1007/s11051-010-0054-8

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