Process Simulation

Process simulation (TCAD—Technology Computer-Aided Design) models how fabrication process steps affect device structure and properties, enabling virtual process development and optimization. Simulation scope: (1) Process simulation—model each fab step (implant, diffusion, oxidation, deposition, etch, CMP) to predict 2D/3D device structure; (2) Device simulation—solve semiconductor equations on the structure to predict electrical characteristics; (3) Coupled process-device—full flow from process recipe to I-V curves. Process simulation physics: (1) Ion implantation—Monte Carlo simulation of ion trajectories, damage, channeling; (2) Diffusion—solve drift-diffusion equations for dopant redistribution during anneal; (3) Oxidation—Deal-Grove model for oxide growth, stress-dependent oxidation; (4) Deposition—ballistic transport (PVD), surface reaction kinetics (CVD/ALD); (5) Etching—physical sputtering + chemical etching models; (6) CMP—Preston equation with pattern density effects. Device simulation: (1) Poisson equation—electrostatic potential; (2) Carrier continuity—electron and hole transport; (3) Quantum corrections—density gradient for thin channels; (4) Mobility models—scattering mechanisms. Tools: Synopsys Sentaurus Process/Device, Silvaco Victory Process/Device. Applications: (1) New technology development—optimize FinFET/GAA structures virtually; (2) Process window analysis—sensitivity to recipe variations; (3) Failure analysis—simulate defect mechanisms; (4) Design technology co-optimization (DTCO)—joint process-design optimization. Calibration: match simulation to silicon measurements using physical model parameters. Significant cost and time savings—evaluate hundreds of process variations computationally versus expensive silicon experiments.