Over the past decade, 3-D process simulation, which is central to the 3-D Technology Computer-Aided Design (3-D TCAD) approach, has severely limited the scope and applicability of TCAD to circuits with a small number of field-effect transistors, owing to its prohibitively high computational costs for large layouts. Due to rapidly changing process recipes and shorter production cycles in the industry, design-time optimization and iterative layout-3-D TCAD exploration for yield-critical or yield-characterizing circuits, such as static random-access memories (SRAMs), ring oscillators, and others, is currently impossible in a practical time frame. In this paper, we architect a novel layout/process/device-independent TCAD methodology in the Sentaurus tool suite to overcome the process simulation barrier for accurate 3-D TCAD structure generation. We adopt an automated structure synthesis (SS) approach, thereby bypassing the need for repetitive 3-D process simulations for different layouts or different versions of the same layout. Results for 32-nm bulk process simulations versus SS and 32-nm silicon-on-insulator (SOI) hardware measurements versus corresponding synthesized structures indicate that the method is an excellent substitute to 3-D process simulation of large layouts, with extremely favorable time and memory scaling behavior. Finally, the robustness and scalability of the proposed abstractions are highlighted through the synthesis of 22-nm SOI 6T FinFET SRAMs and ring oscillator structures.