Feb 24, 2021 Virtual

Ellipsometric Critical Dimension Metrology Employing Mid-Infrared Wavelengths for High-Aspect-Ratio Channel Hole Module Etch Processes

Andy Antonelli

Presentation at SPIE Advanced Lithography
12:30pm — 1:00pm

A novel mid-infrared critical dimension (IRCD) metrology has been developed on a platform suitable for fab production. Compared to traditional optical critical dimension (OCD) technology based on ultraviolet, visible, and near-IR light, the IRCD system exploits unique optical properties of common semiconductor fab materials in the mid-infrared to enable accurate measurements of high-aspect-ratio etched features. In this paper, we will show two examples of critical dry etch steps in 3D NAND channel formation module of an advanced node that require nondestructive process control: (1) carbon hardmask etch and (2) channel hole active area etch.