“…The application of amorphous carbon as an alternative hard mask for conductive or dielectric underlayer HAR etching has been introduced as a means of addressing the limitations associated with conventional single-layer hard masks based on silicon. − The utilization of an amorphous carbon layer (ACL) as an etching mask in nanoscale plasma etching patterning is facilitated by its impressive physical properties, including a high melting point, exceptional hardness, and resistance to corrosion and etching in Cl- or F-containing gases. Additionally, in both current and next-generation semiconductor processing, the ACL hard mask, in conjunction with a complex gas mixed plasma, can be leveraged to achieve high etching selectivity in HAR etching. − In industrial semiconductor plasma etching, three or more complex gas mixtures, which are based on inert gases such as argon and composed of a combination of oxygen, C x F y , and C x H y F z gases, are used to control the etch profile and selectivity. , In a complex gas mixture, inert gas is injected to control the plasma density and degree of dissociation rate, and a trace amount of oxygen gas is injected to control the degree of precursors and deposited polymers produced in the plasma. , However, the high removability of the ACL by oxygen can result in unwanted sidewall etching of the ACL hard mask when exposed to a processing plasma containing oxygen gas, leading to a distorted etch profile and increased pattern opening.…”