TCAD Leakage Current Analysis of a 45 nm MOSFET Structure with a High-k Dielectric
The models of electrophysical effects built-into Sentaurus TCAD have been tested. The models providing an adequate modeling of deep submicron high-k MOSFETs have been selected. The gate and drain leakage currents for 45 nm MOSFETs with polysilicon gate oxide and SiO2, SiO2/HfO2 and HfO2 gate dielectrics have been calculated using TCAD. It has been shown that the replacement of the traditional SiO2 gate by an equivalent HfO2 dielectric reduces the gate leakage current by several orders of magnitude due to the elimination of the impact of the tunneling effect. Besides, the threshold voltage, saturation drain current, mobility, transconductance, etc., degrade within a range of 10–20%.
For the correct accounting of joint effects of radiation and temperature on characteristics of MOSFETs with the help of TCAD system the nonlinear correction coefficient which considers change of concentration of traps from temperature is entered into model of traps volume density in oxide.
Hardware-software subsystem designed for MOSFETs characteristic measurement and SPICE model parameter extraction taking into account radiation effects is presented. Parts of the system are described. The macromodel approach is used to account for radiation effects in MOSFET modeling. Particularities of the account for radiation effects in MOSFETs within the measurement and model parameter extraction procedures are emphasized. Application of the subsystem is illustrated on the example of radiation hardened 0.25 μm SOI MOSFET test structures.
Quasi-3D model for calculation of radiation leakage currents in modern submicron SOI MOSFET structures is proposed. Instead of the fully 3D modeling is proposed to solve two tasks: 2D modeling of the traditional MOSFET cross-section and 3D modeling of the side parasitic transistor. The radiation-induced leakage current simulation in the 0.35 μm SOI MOSFET structure with taking account ionizing radiation with a dose of up to 500 krad was simulated. The results of the simulation show that in comparison with the traditional fully 3D modeling, which requires 11 hours of computer time, the computer time for the IdVg characteristic was reduced to 71 minutes (i.e. the computer time decreased by 9 times).
The paper describes the features of an automated system for measurement and processing of electrical characteristics of BJTs and MOS transistors in the presence of thermal and radiation effects. Automation is made possible with employing of long measurement cables and a ramified scripting system. The system is based on a set of measuring instruments, methods of measurements and processing of results for transistors of various types. Shown are the examples of the system usage for studying BJTs and MOSFETs, determining the SPICE-model parameters.
Approaches to modeling a tsunami of meteoric origin are discussed. A brief overview of the asteroid and meteorite danger to the Earth is given. Formulas assessing the parameters of the tsunami caused by an asteroid entering the water are derived. The results of the numerical simulation of the effect of the angle of entry of the body into water on the characteristics of the resulting waves in the near field are given. The model based on the Navier–Stokes equations for multiphase flows with a free surface is used in calculations. The dimensions of perturbation are studied and the regularities of changes in the parameters of the source are discovered.
Generalized error-locating codes are discussed. An algorithm for calculation of the upper bound of the probability of erroneous decoding for known code parameters and the input error probability is given. Based on this algorithm, an algorithm for selection of the code parameters for a specified design and input and output error probabilities is constructed. The lower bound of the probability of erroneous decoding is given. Examples of the dependence of the probability of erroneous decoding on the input error probability are given and the behavior of the obtained curves is explained.
The dynamics of a two-component Davydov-Scott (DS) soliton with a small mismatch of the initial location or velocity of the high-frequency (HF) component was investigated within the framework of the Zakharov-type system of two coupled equations for the HF and low-frequency (LF) fields. In this system, the HF field is described by the linear Schrödinger equation with the potential generated by the LF component varying in time and space. The LF component in this system is described by the Korteweg-de Vries equation with a term of quadratic influence of the HF field on the LF field. The frequency of the DS soliton`s component oscillation was found analytically using the balance equation. The perturbed DS soliton was shown to be stable. The analytical results were confirmed by numerical simulations.
Radiation conditions are described for various space regions, radiation-induced effects in spacecraft materials and equipment components are considered and information on theoretical, computational, and experimental methods for studying radiation effects are presented. The peculiarities of radiation effects on nanostructures and some problems related to modeling and radiation testing of such structures are considered.
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.