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http://dx.doi.org/10.4191/kcers.2012.49.6.631

A Study of the Memory Characteristics of Al2O3/Y2O3/SiO2 Multi-Stacked Films with Different Tunnel Oxide Thicknesses  

Jung, Hye Young (Department of Materials Science and Engineering, Yonsei University)
Choi, Yoo Youl (Department of Materials Science and Engineering, Yonsei University)
Kim, Hyung Keun (Department of Materials Science and Engineering, Yonsei University)
Choi, Doo Jin (Department of Materials Science and Engineering, Yonsei University)
Publication Information
Journal of the Korean Ceramic Society / v.49, no.6, 2012 , pp. 631-636 More about this Journal
Abstract
Conventional SONOS (poly-silicon/oxide/nitride/oxide/silicon) type memory is associated with a retention issue due to the continuous demand for scaled-down devices. In this study, $Al_2O_3/Y_2O_3/SiO_2$ (AYO) multilayer structures using a high-k $Y_2O_3$ film as a charge-trapping layer were fabricated for nonvolatile memory applications. This work focused on improving the retention properties using a $Y_2O_3$ layer with different tunnel oxide thickness ranging from 3 nm to 5 nm created by metal organic chemical vapor deposition (MOCVD). The electrical properties and reliabilities of each specimen were evaluated. The results showed that the $Y_2O_3$ with 4 nm $SiO_2$ tunnel oxide layer had the largest memory window of 1.29 V. In addition, all specimens exhibited stable endurance characteristics (program/erasecycles up to $10^4$) due to the superior charge-trapping characteristics of $Y_2O_3$. We expect that these high-k $Y_2O_3$ films can be candidates to replace $Si_3N_4$ films as the charge-trapping layer in SONOS-type flash memory devices.
Keywords
Charge trap flash; $Y_2O_3$; Tunnel oxide; High-k dielectrics; SONOS;
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Times Cited By KSCI : 1  (Citation Analysis)
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