A dial-an-operator approach to simulation of impurity diffusion in semiconductors

Thermal processing is used in semiconductor manufacturing to anneal crystal damage caused by implant and to electrically activate the impurities that were introduced to form devices. The continuing size reduction in devices has greatly limited both the temperature and time available for thermal processing in order to limit the motion of impurities during thermal processing steps. Physical effects that were previously unknown or considered to be second order are becoming the dominant factors in the redistribution of dopants during thermal processing. Consequently, the models for these effects are becoming increasingly more complex, and the semiconductor industry is relying more on simulation to accurately predict the movement of dopants during processing.; The traditional approaches to the implementation of semiconductor diffusion models in simulation programs have not scaled well with the increasing complexity of these models. A new approach, designed to support rapid prototyping of equation-based diffusion models, has been implemented in the ALAMODE simulation program. This approach is based on a dial-an-operator paradigm in which simulation models are built from libraries of reusable components and eliminates the burdens of discretization and linearization for the model developer.; The requirements for building an implementation based on this approach are discussed, with particular attention to representation of an equation-based model, robust methods for numerical discretization, design issues specific to simulation software, and efficiency of the implementation. Simulation results are presented for a representative set of semiconductor diffusion models that have been scripted for ALAMODE, including models with fully kinetic treatment of extended defects.