Volume 2, No. 2, December, 2014
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Nanoscopic Study of HfO2 Based HK Dielectric Stacks and Its Failure Analysis

K. Shubhakar 1, 2, N. Raghavan 1, and K. L. Pey 1
1. Singapore University of Technology and Design, 20 Dover Drive, Singapore 138682
2. Division of Microelectronics, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798
Abstract—In this invited paper, we present local electrical characteristics, degradation phenomenon and breakdown analysis of polycrystalline HfO2 dielectric stacks at nanometer scale resolution. Grain boundaries (GBs) in polycrystalline high-κ (HK) dielectric films play a major role in the performance and reliability metrics of HK based advanced metal-oxide-semiconductor (MOS) devices. Hence, it is important to study the degradation and breakdown phenomenon in polycrystalline HfO2 dielectric stacks. The nanoscale localized dielectric breakdown (BD) events are analysed using conductive-atomic force microscopy (C-AFM) and transmission electron microscopy (TEM) techniques. Results show an enhanced trap generation and faster degradation of polycrystalline HfO2 gate dielectrics at GB sites as compared to the bulk (grain) regions. A new technique is adopted to induce the degradation and BD of the HfO2 dielectric locally using a combined scanning tunnelling microscopy/scanning electron microscopy nano-probing system. This method of analysis is very useful in studying the nature of the breakdown events in dielectrics, elucidating the structural changes of the dielectric and the role of the gate electrode in dielectric BD events.
 
Index Terms—dielectric, grain boundary, high-κ, conductive-AFM, breakdown

Cite: K. Shubhakar, N. Raghavan, and K. L. Pey, "Nanoscopic Study of HfO2 Based HK Dielectric Stacks and Its Failure Analysis," International Journal of Materials Science and Engineering, Vol. 2, No. 2, pp. 81-86, December 2014. doi: 10.12720/ijmse.2.2.81-86

General Information

ISSN: 2315-4527
Editor-in-Chief: Prof. Emeritus Dato' Dr. Muhammad Yahaya
DOI: 10.17706/ijmse
Abstracting/ Indexing: Ulrich's Periodicals Directory, Google Scholar, Crossref
E-mail: ijmse@iap.org