We present a topographic simulation platform that simultaneously considers 3D surface movement, neutral and ion transport, and surface reactions in plasma high-aspect-ratio (HAR) oxide etching. The hash map data structure is considered for an effective 3D level-set algorithm with parallelized computations to calculate surface moving speed. Neutral and ion transport within nanoscale semiconductor geometry is parallelized with a graphics processing unit (GPU) so that the speedup ratio, as compared to a single central processing unit (CPU), is approximately 200. The surface reaction based on a two-layer model was incorporated into a 3D feature profile simulation platform with CPU parallelization. Finally, our simulation platform demonstrates that adaptive surface meshing can drastically decrease the computational load with a parallelized numerical platform.