Etching characteristics of amorphous carbon hard masks under inductively coupled oxygen plasmas

Amorphous carbon layers (ACLs) are widely used as hard masks in high-aspect-ratio semiconductor etching due to their excellent durability. Their etching behavior is highly sensitive to oxygen concentration, directly affecting the profile of underlying layers. This study investigates the chemical etching of ACLs under inductively coupled oxygen plasma by varying external conditions. Etch profiles were analyzed using field-emission scanning electron microscopy, and the etching mechanism was characterized through oxygen radical density measurements and molecular dynamics simulations.