Создание IBIS моделей цифровых микросхем с учетом воздействия внешних факторов
A compact BSIMSOI-RAD macromodel for SOI/SOS CMOS transistors is developed that takes into account the radiation effects. An automated procedure for determination of macromodel parameters is described and shown to be useful for analyzing radiation hardness of CMOS IC fragments depending on the total absorbed dose. The simulation time is estimated.
Automated electro-thermal analysis is realized in the last version of Mentor Graphics PCB Design System. The special software tool AETA is developed and integrated into the Expedition Enterprise PCB Design System to automate the process of power-temperature traffic between electrical and thermal simulators. Furthermore AETA provides the graphical user interface and the possibility to use the different versions of Mentor Graphics software.
In this study, a new technique of multilevel current stress for investigation thin oxide layers of MOS structures is proposed. This technique allows to investigate the generation and relaxation of positive and negative charges, accumulating in, nano-thickness gate dielectric of MOS structures under many stressing situations. The parameters characterizing the change of charge state in the thin oxide layers of MOS structures during the stress have been monitored by means of time dependence of voltage shift applied to a sample during the injection. In comparison with the conventional techniques our method is nondestructive. We consider this method to provide higher accuracy and to decrease the probability of dielectric breakdown. The application of present technique was carried out during the investigation of charge generation and relaxation, during and after high-field tunnel injection of electrons in thin film of SiO2. The thin oxide layers of MOS structures after plasma and irradiation treatments also are investigated.
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.