3D feature profile simulation of plasma etching process using novel hardmask protection strategies

As the semiconductor industry advances toward next-generation devices, there is an increasing demand for reducing Critical Dimension (CD) and achieving high aspect ratio etching. One promising solution is the use of protective hardmask layer, formed either prior to or during the plasma etching process of target material. However, this strategy faces significant challenges such as unintended 3D shadowing effects introduced by the hardmask with the protective layer during plasma etching of target material. To address these challenges, we simulated the plasma etch process using a well-established 3D feature profile simulation platform which consists of plasma reactor modeling, ballistic transport within the nanoscale profile, surface reaction kinetics, and a 3D moving algorithm. This study investigates the detailed effects of hardmask protection on etch profiles and etch selectivity by analyzing key plasma parameters such as neutral/ion flux, ion energy, and ion incidence angle. The results demonstrate the potential of the novel hardmask strategy in mitigating etch anomalies and offer valuable insights into its practical implementation in high aspect ratio plasma etching processes.