Browsing by Author "Chang, Hua-Gang"

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A Method of Extracting Metal-Gate High-k Material Parameters Featuring Electron Gate Tunneling Current Transition
(2011-04-01)
Hsu, Chih-Yu
;
Chang, Hua-Gang
;
Chen, Ming-Jer
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
For metal-gate high-k dielectrics, there is a transition region in the electron gate tunneling current I(g), as characterized by a plot of dlnI(g)/dV(g) versus V(g). In this paper, we systematically construct a new fitting over the region, which can accurately determine material parameters, including metal work function, high-k electron affinity, and tunneling effective masses of electrons. First of all, a calculation of gate current due to electron direct tunneling and/or Fowler-Nordheim tunneling from an inversion layer is performed, yielding the guidelines of the fitting. Experimental samples are presented with n-channel metal-oxide-semiconductor field-effect transistors having low effective oxide thickness (1.4 nm) TaC/HfSiON/SiON gate stacks. Underlying material parameters are extracted accordingly and remain valid for higher temperature and gate voltage. We also demonstrate that a conventional method without a dlnI(g)/dV(g) fitting might lead to erroneous results. Thus, the dlnI(g)/dV(g) fitting is crucial to metal-gate high-k material parameter assessment.