Temperature distribution in an SOI transistor





To predict the electrical characteristics of semiconductor devices it is necessary to solve Boltzmann's transport equation, which is a seven-dimensional equation in the phase space and provides a semi-classical description of carrier transport. Based on the method of moments, equation systems of different sophistication can be derived, such as the drift-diffusion, energy-transport, or six-moments model. The general-purpose three-dimensional device and circuit simulator Minimos-NT has been developed to solve such moment-based transport models. It furthermore allows to solve the lattice heat flow equation which enables to predict device heating.










Electric potential in a 'smart power' MOSFET




Within the last years Minimos-NT has been extended to a fully three-dimensional device simulator. The PIF (Profile Interchange Format) - based libraries which support two-dimensional structures have been replaced by a more flexible library which supports one-, two-, and three-dimensional structures. A separate module called quantity server provides scalar quantities and vector-valued quantities which may be one-, two-, or three-dimensional according to the dimensionality of the device. Furthermore, transient and AC simulations have been made possible by the implementation of a complex-valued solver system which provides a direct and two iterative solution cores.





Current density in the silicon segment of a FinFET




Minimos-NT allows the simulation of complex device geometries such as FinFETs, which are depleted-substrate devices where a small silicon channel - the fin - is surrounded at two or three sides by a gate electrode, silicon-carbide power MOSFETs, which, due to the wide band gap of silicon-carbide, are better suited for high power and high frequency applications, or advanced smart power SOI devices which are optimized to reach high breakdown voltages.