Plasma Features and Surface Reactions in cryogenic etching using Ar/HF Plasma*

Plasma features and surface reactions in cryogenic etching using Ar/HF plasma, an essential process in high aspect ratio contact (HARC) etching for semiconductor applications. By leveraging the advantages of cryogenic temperatures, such as the formation of a passivation layer, the process minimizes sidewall damage and enhances precision. The research compares conventional and cryogenic etching methods, demonstrating that dual-frequency plasma enhances ion bombardment and improves etching rates. Our simulations use a hybrid plasma equipment model (HPEM) to analyze surface chemistry, with results showing that cryogenic etching at dual frequencies increases both Ar+ and HF+ densities, leading to a more controlled and efficient etch process. Further research is proposed to refine surface chemistry understanding and optimize parameters for higher precision and etching efficiency.