Physically rigorous modeling of internal laser-probing techniques for microstructured semiconductor devices

The space- and time-resolved distributions of charge carriers and temperature in the interior of microstructured semiconductor devices have become accessible to measurement as a variety of internal laser probing techniques has been become available. For a comprehensive theoretical analysis of these novel characterization methods, a physically rigorous model for simulating the entire measurement process is presented in this work. Major steps are the electrothermal device simulation of the sample\´s operating behavior and the calculation of optical-wave propagation through the sample, the lenses, and the aperture holes. We propose a numerically efficient algorithm for simulating wave propagation in large computational domains. The decisive step is the suitable choice of the computational variables which enables a significantly coarser discretization mesh without loosing accuracy. To support the design and the optimization of the experiments, the concept of "virtual experiments" is introduced as the key strategy for a quantitative analysis of the measurement techniques. As an application example, backside laser probing is discussed. It is shown that this technique provides a large measurement range as well as an excellent spatial resolution and, therefore, constitutes a powerful characterization method for a large multitude of different microstructures.