Atomistic simulations of dielectric screening in large scale microelectronic devices at first principles accuracy

The dielectric screening of a microelectronic device and the related capacity-voltage (C-V) relationship is a major component in TCAD (technology computer-aided design) simulations. Traditionally the dielectric screening is described by a macroscopic continuum dielectric function in the Poisson equation. As devices shrink to the nanometer scale, however, atomic-level fluctuations and single defect screenings become crucial, requiring atomic resolved polarization model. Direct first principles methods are impractical at device scale due to their computational expense as well as the nonequilibrium nature of the devices. We introduce an atomic motif-based Poisson solver (AMPS), which leverages atom-specific motifs derived from density functional theory (DFT) to capture atomic-scale polarization while self-consistently solving the long-range Coulomb potential. AMPS balances accuracy and computational efficiency, demonstrating high flexibility across tested configurations, including 3-nm gate-all-around (GAA) devices with over 20,000 atoms. Using AMPS, we illustrated how electron and hole wavefunctions, as well as their polarizations are influenced by the atomistic interfacial fluctuations at the device level, which is unavailable in traditional continuum simulation methods. This approach unlock s first principles simulation potential for large-scale systems with efficiency comparable to traditional TCAD tools.