Process technology computer aided design (TCAD) is one of the essential drivers of the semiconductor industry, as it allows to predict the feasibility of fabrication of future devices without the need for expensive and time-consuming experiments. For many decades, process TCAD simulations were built on analytical models which were derived based on many years of experiments and measurements on silicon. However, as the industry moves away from silicon due to its physical limitations, and into a quasi-exploratory phase of new materials and geometries, a rethink in the way process models are devised is required. Essentially, a multi-scale approach needs to be investigated, whereby atomistic material models are used to replace the knowledge missing due to a lack of experiments. Such material models are used to provide static as well as dynamic parameters and quantities for mesoscale and continuum models which calculate the shape and doping profile on a more macroscopic scale.
The Christian Doppler Laboratory for Multi-Scale Process Modeling of Semiconductor Devices and Sensors aims to expand on the state-of-the-art in process TCAD by introducing two additional material representations, one for topography simulations such as deposition and etching and a second one for volume problems such as implantation and diffusion. Furthermore, process TCAD models will have to be informed by atomistic calculations which includes a combination of molecular dynamics (MD) and density functional theory (DFT) approaches. Until now, the atomistic simulations served to provide parameter values in order to calibrate the TCAD models. However, this is often insufficient, since important spatial volume effects are lost. Therefore, in this project we will investigate a means to ensure that all relevant material properties are stored and remain accessible throughout the simulation flow in a dynamic way. This will allow to provide a means for the materials used in the simulation to “remember” the effects of the previous steps to which it has been exposed.
