Memory characteristics of Al2O3/La2O3/SiO2 multi-layer structures for charge trap flash devices

Seung Yong Cha, Hyo June Kim, Doo Jin Choi

Research output: Contribution to journalArticle

Abstract

The Charge Trap Flash (CTF) memory device is a replacement candidate for the NAND Flash device. In this study, Pt/Al2O3/La2O3/SiO2/Si multilayer structures with lanthanum oxide charge trap layers were fabricated for nonvolatile memory device applications. Aluminum oxide films were used as blocking oxides for low power consumption in program/erase operations and reduced charge transports through blocking oxide layers. The thicknesses of SiO2 were from 30 Å to 50 Å. From the C-V measurement, the largest memory window of 1.3V was obtained in the 40 Å tunnel oxide specimen, and the 50 Å tunnel oxide specimen showed the smallest memory window. In the cycling test for reliability, the 30 Å tunnel oxide sample showed an abrupt memory window reduction due to a high electric field of 9~10MV/cm through the tunnel oxide while the other samples showed less than a 10% loss of memory window for 104 cycles of program/erase operation. The I-V measurement data of the capacitor structures indicated leakage current values in the order of 10-4 A/cm2 at 1V. These values are small enough to be used in non-volatile memory devices, and the sample with tunnel oxide formed at 850°C showed superior memory characteristics compared to the sample with 750°C tunnel oxide due to higher concentration of trap sites at the interface region originating from the rough interface.

Original languageEnglish
Pages (from-to)462-467
Number of pages6
JournalKorean Journal of Materials Research
Volume19
Issue number9
DOIs
Publication statusPublished - 2009 Dec 9

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Oxides
Data storage equipment
Tunnels
Lanthanum oxides
Flash memory
Aluminum Oxide
Leakage currents
Oxide films
Charge transfer
Multilayers
Electric power utilization
Capacitors
Electric fields
Aluminum

All Science Journal Classification (ASJC) codes

  • Materials Science(all)

Cite this

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title = "Memory characteristics of Al2O3/La2O3/SiO2 multi-layer structures for charge trap flash devices",
abstract = "The Charge Trap Flash (CTF) memory device is a replacement candidate for the NAND Flash device. In this study, Pt/Al2O3/La2O3/SiO2/Si multilayer structures with lanthanum oxide charge trap layers were fabricated for nonvolatile memory device applications. Aluminum oxide films were used as blocking oxides for low power consumption in program/erase operations and reduced charge transports through blocking oxide layers. The thicknesses of SiO2 were from 30 {\AA} to 50 {\AA}. From the C-V measurement, the largest memory window of 1.3V was obtained in the 40 {\AA} tunnel oxide specimen, and the 50 {\AA} tunnel oxide specimen showed the smallest memory window. In the cycling test for reliability, the 30 {\AA} tunnel oxide sample showed an abrupt memory window reduction due to a high electric field of 9~10MV/cm through the tunnel oxide while the other samples showed less than a 10{\%} loss of memory window for 104 cycles of program/erase operation. The I-V measurement data of the capacitor structures indicated leakage current values in the order of 10-4 A/cm2 at 1V. These values are small enough to be used in non-volatile memory devices, and the sample with tunnel oxide formed at 850°C showed superior memory characteristics compared to the sample with 750°C tunnel oxide due to higher concentration of trap sites at the interface region originating from the rough interface.",
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Memory characteristics of Al2O3/La2O3/SiO2 multi-layer structures for charge trap flash devices. / Cha, Seung Yong; Kim, Hyo June; Choi, Doo Jin.

In: Korean Journal of Materials Research, Vol. 19, No. 9, 09.12.2009, p. 462-467.

Research output: Contribution to journalArticle

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