TCAD tools for efficient 3D simulations of geometry effects in floating-gate structures

In the present work, we demonstrate the use of appropriate 3D TCAD tools for process emulation and device simulation of floating-gate structures under consideration of process-induced geometry effects. The floating to control gate capacitance of representative dummy structures is extracted by full 3D simulation, with particular focus on effects related to the sidewall oxide, the spacer, and the bending radius of the polysilicon edges. The proposed methodology is assessed and compared with methods currently used in the industry. All simulations are performed by an innovative device simulation tool, a 3D process emulator, and a mesh generator that generates boundary-conforming meshes, allowing for very fine descriptions of the complex geometry.