A Method of Extracting Metal-Gate High-k Material Parameters Featuring Electron Gate Tunneling Current Transition

作者：Hsu Chih Yu^*; Chang Hua Gang; Chen Ming Jer

来源：IEEE Transactions on Electron Devices, 2011, 58(4): 953-959.

DOI：10.1109/TED.2011.2105270

• HfSiON
• high-k
• metal gate
• metal-oxide-semiconductor field-effect transistors (MOSFETs)
• tunneling

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.

• 出版日期2011-4