Title: Kink effect for 28 nm n-channel field-effect transistors after decoupled plasma nitridation treatment with annealing temperatures

Authors: Shea-Jue Wang; Mu-Chun Wang; Win-Der Lee; Wen-Sheng Chen; Heng-Sheng Huang; Shuang-Yuan Chen; L.S. Huang; Chuan-Hsi Liu

Addresses: Department of Materials and Resources Engineering, National Taipei University of Technology, 1, Sec. 3, Zhongxiao E. Rd., Taipei 10608, Taiwan ' Department of Mechanical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan; Department of Electronic Engineering, Minghsin University of Science and Technology, Hsinchu 30401, Taiwan ' Department of Electrical Engineering, Lee-Ming Institute of Technology, New Taipei City 24305, Taiwan ' Department of Mechanical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan ' Department of Mechanical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan ' Department of Mechanical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan ' Reliability Dept./ATD Device Division, United Microelectronics Corporation, Hsinchu 30078, Taiwan ' Department of Mechatronic Technology, National Taiwan Normal University, Taipei 10610, Taiwan

Abstract: The kink effect of drain leakage based on gated diode measurement metrology for the tested nMOSFETs with 28 nm HK/MG, gate-last and PDA or DPN nitridation processes was observed at VG around −0.6 V when the gate voltage was swept from −Vcc to 0.2 volt as VD = 0.1 V. Nevertheless, this interesting phenomenon was not evident as the gate voltage was reversely swept from 0.2 volt to -Vcc. The chief mechanism in speculation can be illustrated by the electrons coming from drain inducing capture-and-emission behaviour by the channel interface traps near the drain junction. While VG changes from −Vcc towards +0.2 V, interface states near valence band become lower than Fermi-level of silicon substrate. Electrons flow from drain to fill these interface states so that drive current (ID) increases. On the contrary, as VG changes from +0.2 V to −Vcc, the trapped electrons are recombined with holes from substrate so that ID is not affected. This kink effect for all of tested devices is not very distinct far and near. When the Poole-Frenkel (P-F) tunnelling electrons coming from gate to drain are evident in leakage, especially at the long-channel device, this effect will be probably counteracted, exhibited at the electrical characteristics of PDA group.

Keywords: DPN; drain leakage; gate-last; gate leakage; high-k; interface state; kink effect; metal gate; field-effect transistors; decoupled plasma nitridation; annealing temperatures; nMOSFETs.

DOI: 10.1504/IJNT.2015.066194

International Journal of Nanotechnology, 2015 Vol.12 No.1/2, pp.59 - 73

Published online: 04 Dec 2014 *

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