Влияние электронного и гамма-излучений на статические характеристики кремниевых СВЧ биполярных транзисторов
The article highlights the status of TCAD and SPICE modeling of CMOS, SOI CMOS, SiGe BiCMOS VLSI components intended for operation under the influence of radiation (neutrons, electrons, protons, y- and X-ray, single particle, pulsed radiation), high (up to +300°C) and low (up to –200°C) temperatures. TCAD and SPICE models of BJTs and MOSFETs, and methods for determining their parameters have been described. Further directions of TCAD and SPICE modeling of IС components have been considered.
A new interatomic potential for a uranium–molybdenum system with xenon is developed in the framework of an embedded atom model using a force matching technique and a dataset of ab initio atomic forces. The verification of the potential proves that it is suitable for the investigation of various compounds existing in the system as well as for simulation of pure elements: U, Mo and Xe. Computed lattice constants, thermal expansion coefficients, elastic properties and melting temperatures of U, Mo and Xe are consistent with the experimentally measured values. The energies of the point defect formation in pure U and Mo are proved to be comparable to the density-functional theory calculations. We compare this new U–Mo–Xe potential with the previously developed U and Mo–Xe potentials. A comparative study between the different potential functions is provided. The key purpose of the new model is to study the atomistic processes of defect evolution taking place in the U–Mo nuclear fuel. Here we use the potential to simulate bcc alloys containing 10 wt% of intermetallic Mo and U2Mo.
The main content of the training manual is:consideration of the issues of the effect of radiation creating structural defects on the main parameters of bipolar transistors, Consider issues related to the influence of ionization factors on the operation of transistors (radiation transients), the effect of nuclear reactions and fast annealing on the parameters of transistors is considered; Classification of radiation effects in bipolar transistors is given.
A method of account for radiation effects (total dose and particle fluence) in signal integrity analysis of digital system by using IBIS model is presented. It is shown that account for these effects in IBIS models can be performed by correction the input impedances of protection circuits (GND_Clamp and POWER_Clamp), output MOSFETs (PULL_UP, PULL_DOWN) characteristics and RAMP parameters in according with the known physical relations. Examples of digital IC output and crosstalk signals simulation with HyperLynx software using the created IBIS model is presented.
The effects of proton irradiation on SiGe heterojunction bipolar transistor (HBT) are investigated using Synopsys/ISE TCAD tool. To account for the impact of proton irradiation models for carrier lifetime degradation under irradiation are included in the program. The results of modeling the impact of protons of different energies are presented. For SiGe HBT increase in the base current for low-energy protons is more intense than for high-energy protons. We also present the simulation results of SiGe HBT dc and ac performance after proton exposure. The simulation results are in good agreement with experimental data.
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.
An EKV-RAD macromodel for SOI/SOS MOSFET with account for radiation effects is developed using a subcircuit approach. As an addition to the standard version of the EKV model 1) radiation dependencies of parameters VTO, GAMMA, KP, E0 are introduced and 2) additional circuit elements to account for floating-body effects and radiation-induced leakage currents under static and dynamic radiation influence are connected. Maximum simulation error is 5–7% in the dose range up to 1 Mrad. It is shown that EKV-RAD spends less CPU time by 15–30% for analog and 40–50% for digital SOI/SOS CMOS circuits simulations compared to BSIMSOI-RAD model.