The progress and challenges of threshold voltage control of high-k/metal-gated devices for advanced technologies (Invited Paper)

This paper discusses recent progress in and challenges of threshold voltage control for advanced high-k/metal-gated (HKMG) devices. It presents the impact on threshold voltage (V_t) control of incorporating La and Al into HKMG devices. A dipole moment model explaining V_t tuning of HfSiON/metal-gated MOSFETs is proposed. In addition, a dual channel scheme that allows La₂O₃ capping in NMOS and a SiGe channel in PMOS to achieve acceptable V_t for HKMG CMOS devices will be discussed. Also shown is the impact of the robustness of the SiO₂/Si interface on the HKMG MOSFET V_t-equivalent oxide thickness (EOT) roll-off. Finally, techniques to improve the interface quality of a HKMG stack will be discussed.     

Decoupling the Fermi-level pinning effect and intrinsic limitations on p-type effective work function metal electrodes

A review of literature combined with recent experimental results addressing the intrinsic and extrinsic factors controlling the effective work function (EWF) of metal gate electrodes on Hf-based high-K dielectrics is discussed. Through a systematic study including accurate extraction of EWF, our observations suggest, unlike popularly perceived, intrinsic E_f-pinning does not limit the EWF tuning on high-K. Also, a critical issue challenging the maintenance of high EWF metals at low effective oxide thicknesses (EOT), due to a new phenomena described as the “V_fb roll-off”, is reported for the first time.     

A.C. field effect study on PbTe films grown by hot wall epitaxy technique

The field effect mobility on the free surface of PbTe films grown by hot wall epitaxy (HWE) technique ona KCl substrate was studied as a function of frequency in the range 40–200 kHz at different temperatures from 98–156 K. Using Garrett's theory of the frequency dependence of field-effect mobility, the relaxation times of surface states were found to vary from 1.84 to 0.96 μsec in the above temperature range. From Rupprecht's relation on temperature dependence of relaxation times, the energy level of surface states was found to be 0.02 eV below the conduction band with an effective capture cross section of the order 10^?19 cm².     

Characteristics of n-CuInSe2/Au Schottky diodes

The n-CuInSe₂/Au point-contact Schottky diode was studied using current-voltage and capacitance-voltage measurements. Various important physical parameters of these diodes were derived from both measurements, and these values are comparable with the results reported on planar Schottky diodes.     

Comparison of effective work function extraction methods using capacitance and current measurement techniques

The effective work function (EWF) extracted on terraced oxide structures by capacitance-voltage-based techniques was compared with the work function calculated from the barrier height extracted by current-voltage measurements. The results show a reasonable correlation-within /spl plusmn/ 0.1 eV-in the EWF values for various metal gate electrodes, validating both techniques for EWF extraction.     

Structural, dielectric, impedance and optical properties of CaBi2B2O7 glasses and glass-nanocrystal composites

Optically clear glasses were fabricated by quenching the melt of CaCO₃–Bi₂O₃–B₂O₃ (in equimolecular ratio). The amorphous and glassy characteristics of the as-quenched samples were confirmed via the X-ray powder diffraction (XRD) and differential scanning calorimetric (DSC) studies. These glasses were found to have high thermal stability parameter (S). The optical transmission studies carried out in the 200–2500 nm wavelength range confirmed both the as-quenched and heat-treated samples to be transparent between 400 nm and 2500 nm. The glass-plates that were heat-treated just above the glass transition temperature (723 K) for 6 h retained ≈60% transparency despite having nano-crystallites (≈50–100 nm) of CaBi₂B₂O₇ (CBBO) as confirmed by both the XRD and transmission electron microscopy (TEM) studies. The dielectric properties and impedance characteristics of the as-quenched and heat-treated (723 K/6 h) samples were studied as a function of frequency at different temperatures. Cole–Cole equation was employed to rationalize the impedance data.     

Studies on the kinetics of photo-initiated radical polymerisation of modified epoxy resin

The diglycidyl ether of bisphenol-A (DGEBPA) was modified by acrylic acid. The reaction between the active epoxy groups of DGEBPA and the carboxylic group of acrylic acid was catalysed by triphenyl phosphine to prepare di(vinyl-2-hydroxypropanoate) ether of bisphenol-A (DEBA). The DEBA so formed was co-polymerised with 2-ethylhexylacrylate using benzophenone as the photo-initiator to yield a flexible polymer. The kinetics of the photo-initiated radical polymerisation was studied by a new technique called differential photo-calorimetery and the results thus obtained were analysed to determine the Arrhenius activation energy and pre-exponential factor.     

Auto-tuning of FOPI Controllers for TITO Processes with Experimental Validation

Machine Intelligence Research - In this paper, the auto-tuning of a fractional order proportional and integral (FOPI) controller is proposed and experimentally validated for two-input two-output...     

Non-overlapped blockwise interpolated local binary pattern as periocular feature

Multimedia Tools and Applications - Most of the prominent features of human face are present in the ocular area, referred as the periocular region. Complex and dense features in these regions makes...     

Quantum-inspired binary chaotic salp swarm algorithm (QBCSSA)-based dynamic task scheduling for multiprocessor cloud computing systems

The Journal of Supercomputing - Scheduling in multiprocessor computing systems is experiencing prolific challenges in datacenters due to the alarmingly growing need for dynamic on-demand resource...