Investigation of Low-Frequency Noise in High-k First/ Metal Gate Last HfO

SSDM 2014, Tsukuba International Congress Center, Tsukuba, Ibaraki, Japan, Sep. 10, 2014

Po-Chin HUANG, National Cheng Kung University, Tainan City, Taiwan

Investigation of Low-Frequency Noise in High-k First/

Metal Gate Last HfO

and ZrO

nMOSFETs

C. H. Hsu, C. W. Yang, C. G. Chen, O. Cheng

Central R&D Division, UMC, Taiwan

B. C. Wang, S. C. Tsai, J. F. Chen, S. J. Chang⁺, S. P. Chang⁺, Po-Chin Huang⁺

Institute of Microelectronics and Department of Electrical Engineering,

& ⁺Advanced Optoelectronic Technology Center National Cheng Kung University, Taiwan

S. L. Wu, Y. Y. Lu

Department of Electronic Engineering, Cheng Shiu University, Taiwan

SSDM 2014, Tsukuba International Congress Center, Tsukuba, Ibaraki, Japan, Sep. 10, 2014

Po-Chin HUANG, National Cheng Kung University, Tainan City, Taiwan

Result of 1/ f Noise

 The obvious “hump” shape in HfO₂ device implies serious trapping and detrapping behaviors.

 Higher S_ID/I_D² level in HfO₂ device  Higher oxide trap density.

 Higher frequency exponential factor of γ (SID/I_D² ~1/f ^γ) in HfO₂ device

Higher density ratio of the interior trap to the interface trap.

 1/f noise model:

Carrier number fluctuation (ΔN) in HfO2 device

Correlated number-mobility fluctuation (ΔN+ Δμ) in ZrO2 device

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SSDM 2014, Tsukuba International Congress Center, Tsukuba, Ibaraki, Japan, Sep. 10, 2014

Po-Chin HUANG, National Cheng Kung University, Tainan City, Taiwan

Results of RTS Noise and Trap Properties

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 I_D fluctuation in RTS Noise

 Oxide Trap Density

 Trap location

 In ZrO₂ nMOSFETs

 Reduced oxygen vacancy concentration, which may play a role as the electron trapping site

 Improved oxide quality due to lower interior trap density

 Improved low-frequency noise characteristics