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Low-frequency charge pumping method is used for examining the transient charging and discharging of border traps in the dual-layer Hf[O.sub.2]/Si[O.sub.2] high-k gate stack. The occurrence of both transient charging and discharging of border traps is essential for constituting the charge pumping current.

A systematic study of tunneling leakage current in metal gate MOSFETs and how it is affected by the work function of the metal gate electrodes is presented. The results show good agreements with measurements for both SiO2 and HfO2 gate dielectrics with TaN electrodes.

A one-band self-consistent effective mass approximation (EMA) for hole quantization in p-MOSFET is described and discussed.

Hole tunneling can be used to project the electrical oxide thickness scaling limit of the oxynitride/oxide gate stack dielectrics used in p-MOSFETs. The validity of the model is verified by the excellent agreement between the simulated and experimental results.

An introduction of a simple and efficient model is given to study the effects of the hole quantization in the inversion layer of p-MOS devices. The fabrication of MOS device is obtained on silicon substrate. The justification of this model is given by applying it to the capacitance of hole inversion layer and the threshold voltage shifts due to quantum mechanical (QM) effect.

A model is proposed for examining hole-quanization effects in inversion layers of p-metal-oxide semiconductor (p-MOS) devices. It relies on a six-band effective mass equation and a zigzag potential.

Transient charging and discharging of border traps in the dual-layer HfO2/SiO2 high-κ gate stack have been extensively studied by the low-frequency charge pumping method with various input pulse waveforms. It has been demonstrated that the exchange of charge carriers mainly occurs through the direct tunneling between the Si conduction band states and border traps in the HfO2 high-κ dielectric within the transient charging and discharging stages in one pulse cycle. Moreover, the transient charging and discharging behaviors could be observed in the time scale of 10-8-10-4 s and well described by the charge trapping/detrapping model with dispersive capture/emission time constants used in static positive bias stress. Finally, the frequency and voltage dependencies of the border trap area density could also be transformed into the spatial and energetic distribution of border traps as a smoothed 3-D mesh profiling. [ABSTRACT FROM AUTHOR]

We present a systematic study of tunneling leakage current in metal gate MOSFETs and how it is affected by the work function of the metal gate electrodes. Physical models used for simulations were corroborated by experimental results from SiO2 and HfO2 gate dielectrics with TaN electrodes. In bulk CMOS results show that, at the same capacitance equivalent oxide thickness (CET) at inversion, replacing a poly-Si gate by metal reduces: the gate leakage appreciably by one to two orders of magnitude due to the elimination of polysilicon gate depletion. It is also found that the work function ф β of a metal! gate affects tunneling characteristics in MOSFETS. It is particularly significant when the transistor is biased at accumulation. Specifically, the increase of ф β reduces the gate-to-channel tunneling in off-biased n-FET and the use of a metal gate with midgap ф β results in a significant reduction of gate to source/drain extension (SDE) tunneling in both n- and p-FETs. Compared to bulk YET, double gate (DG); VET1 has much lower off-state leakage due to the smaller gate to SDE tunneling. This reduction in off-state leakage can be as much as three orders of magnitude when high-κ gate dielectric is used. Finally, the benefits of employing metal gate DG structure in future CMOS scaling are discussed. [ABSTRACT FROM AUTHOR]

Presents the systematic investigation of the hole tunneling current through ultrathin oxynitride/oxide stack gate dielectrics in p-metal oxide semiconductor field-effect transistors (p-MOSFET). Effects of the increase in the dielectric constant; Energy band diagram of a p-MOSFET with oxide gate dielectric; Comparison of simulated and measured hole tunneling current through oxide and nitride gate dielectrics.