Before revision:  Specifically, we develop (1) eDensity-3D: an electrostatics based 3D placement density function with globally uniform smoothness (2) a 3D numerical solution with improved spectral formulation (3) a 3D nonlinear pre conditioner for convergence acceleration (4) interleaved 2D-3D placement for quality and efficiency enhancement.
After revision:  Specifically, we develop (1) eDensity-3D: an electrostatics based 3D placement density function with globally uniform smoothness (2) a 3D numerical solution with improved spectral formulation (3) a 3D nonlinear pre-conditioner for convergence acceleration (4) interleaved 2D-3D placement for quality and efficiency enhancement.