Materials 2014, 7(3), 2370-2381; doi:10.3390/ma7032370
Article

Electrical Characteristics of the Uniaxial-Strained nMOSFET with a Fluorinated HfO2/SiON Gate Stack

Received: 3 January 2014; in revised form: 10 March 2014 / Accepted: 12 March 2014 / Published: 20 March 2014
(This article belongs to the Special Issue High-k Materials and Devices)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: The channel fluorine implantation (CFI) process was integrated with the Si3N4 contact etch stop layer (SiN CESL) uniaxial-strained n-channel metal-oxide-semiconductor field-effect transistor (nMOSFET) with the hafnium oxide/silicon oxynitride (HfO2/SiON) gate stack. The SiN CESL process clearly improves basic electrical performance, due to induced uniaxial tensile strain within the channel. However, further integrating of the CFI process with the SiN CESL-strained nMOSFET exhibits nearly identical transconductance, subthreshold swing, drain current, gate leakage and breakdown voltage, which indicates that the strain effect is not affected by the fluorine incorporation. Moreover, hydrogen will diffuse toward the interface during the SiN deposition, then passivate dangling bonds to form weak Si-H bonds, which is detrimental for channel hot electron stress (CHES). Before hydrogen diffusion, fluorine can be used to terminate oxygen vacancies and dangling bonds, which can create stronger Hf-F and Si-F bonds to resist consequent stress. Accordingly, the reliability of constant voltage stress (CVS) and CHES for the SiN CESL uniaxial-strained nMOSFET can be further improved by the fluorinated HfO2/SiON using the CFI process. Nevertheless, the nMOSFET with either the SiN CESL or CFI process exhibits less charge detrapping, which means that a greater part of stress-induced charges would remain in the gate stack after nitrogen (SiN CESL) or fluorine (CFI) incorporation.
Keywords: fluorine; strain; HfO2
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MDPI and ACS Style

Chen, Y.-Y. Electrical Characteristics of the Uniaxial-Strained nMOSFET with a Fluorinated HfO2/SiON Gate Stack. Materials 2014, 7, 2370-2381.

AMA Style

Chen Y-Y. Electrical Characteristics of the Uniaxial-Strained nMOSFET with a Fluorinated HfO2/SiON Gate Stack. Materials. 2014; 7(3):2370-2381.

Chicago/Turabian Style

Chen, Yung-Yu. 2014. "Electrical Characteristics of the Uniaxial-Strained nMOSFET with a Fluorinated HfO2/SiON Gate Stack." Materials 7, no. 3: 2370-2381.

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