Semenovs'ka O. Simulation of electrothermal processes in submicron heterostructures

This dissertation is devoted research of thermal processes and a self-heating effect in powerful submicrometer heterostructures and integrated microcircuits on their basis. The thermal fields design procedure in the transistor, based on the joint decision of physico-topological model equations and the heat conductivity equation in two-dimensional approach is offered. Mathematical models and the algorithms which allow up to construct distributions of temperature along transistor structure, to reveal overheat zones and to specify model parameters at a design stage are created. The self-heating accountable effect up in the transistor technique at the expense of introduction in circuit model of additional ballast resistance and a dependent source is investigated. The dependence of the feedback factor from the ballast resistors nominal value in the base and emitter areas of transistor and recommendations for choosing the optimal values of ballast resistors are defined. Addition, character of influence of self-heating effect a up for the output and frequency characteristics is established. The way of thermal resistance calculation of the submicrometer transistor on its thermal model is developed and patented. The dependence of the crystal transistor thermal resistance on the shape and geometric dimensions of the crystal and the transistor gate, on the operation modes of the transistor, the numbers of doping layers and doping level subgate area. This method has been applied to calculate the thermal resistance of monolithic integrated circuits, depending on the number and arrangements of heat sources on the surface of chips.