TCAD

TCAD, short for Technology Computer-Aided Design, is a family of software tools used to simulate semiconductor fabrication processes and the electrical behavior of devices. It aims to predict performance, understand process variations, and guide design before fabrication. TCAD is commonly divided into Process TCAD, which models manufacturing steps, and Device TCAD, which models device operation by solving electrical and transport equations.

Process TCAD covers diffusion, oxidation, deposition, etching, implantation, and annealing. It uses physical models to predict dopant profiles, film properties, and layer thicknesses as process conditions change. Thermal effects and stresses may be included, as well as defect generation in films.

Device TCAD solves Poisson’s equation with carrier continuity, often using drift-diffusion or more advanced transport models such as hydrodynamic or Monte Carlo methods. It produces current–voltage characteristics, capacitances, breakdown behavior, and variability for devices such as MOSFETs, diodes, and solar cells.

Typical workflow involves defining geometry and materials, specifying process steps, meshing, and running simulations. Results are calibrated to experimental data, and the design or process is iterated to meet targets. Limitations include model approximations, parameter sensitivity, and computational cost.

TCAD is widely used in industry and academia for device development, process integration, design optimization, and reliability studies.