In-Line Critical Dimension and Sidewall Roughness Metrology Study for Compound Nanostructure Process Control by in-Line 3D Atomic Force Microscope

Abstract

Metrology solution for critical dimension and sidewall roughness of compound structure in nondestructive manner is an importantfor better device performance and improving yield. Due to high complexity in SiGe and III-V film stacks with embedded defectsa new metrology solution needs to be evaluated. In-line 3D atomic force microscopy was performed to provide a suitable metrologyfor compound semiconductor process. The technique could measure accurately the height and CD of Fin structures, which hasthe space with of 25 nm and the height of 60 nm. The uniformity of recess height could be measured, which could be interpretedby loading effect of etch process. Sidewall roughness of InGaAs/InP Fin with various CDs were also measured in success andthe technique can differentiate the sidewall roughness changes below 0.1 nm, which were treated at different chemistries andprocesses. In-line 3D AFM could provide a suitable metrology solution not only for the development of compound semiconductordevice, but also its process monitoring.