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