Abstract
As semiconductor devices become smaller, having ultra-smooth and defect-free surfaces is essential to prevent failures and ensure reliability. Therefore, during manufacturing, particularly after Chemical Mechanical
Planarization (CMP), strict cleaning processes are crucial to remove defects caused by residual particles, organic residues, and metallic impurities. This significantly enhances device performance. A major challenge in post-CMP cleaning is removing ceria particles from SiO2 surfaces because of their strong Ce-O-Si bond adhesion. Although there have been advances in cleaning solutions and process optimizations, new ceria-related defects continue to appear as defect detection technologies improve, currently detecting features as small as 45 nm. This highlights the urgent need to better understand the origins and persistence of these defects, which will aid in further advancements in post-CMP cleaning technologies.
The primary goal of my research is to explore the origins and persistence of ceria particles and develop effective removal strategies during post-CMP cleaning. Initially, Atomic Force Microscopy and SEM-EDS confirmed the presence of ceria-related residues, extending beyond typical particle-type defects. These residues consist of small ceria fragments and tribofilm, both of which are byproducts of the polishing process and remain on the film after cleaning. The research aims to enhance cleaning efficiency specifically targeting these ceria fragments and
tribofilm. It will examine the formation and structure of tribofilm to devise preventative strategies during
polishing and removal techniques during cleaning. The study will also focus on the mechanisms behind the removal of small ceria fragments, aiming to enhance cleaning efficacy through a chemical-based approach. This involves analyzing how manipulating the adhesion forces, which cause ceria fragments to persist, affects their removal. Additionally, the impact of operational parameters in brush scrubbing, particularly how the shear force applied can dislodge these fragments, will be investigated.
Monday, 05/20/2024 at 2:30 pm, CAMP 372
https://clarkson.zoom.us/j/95295717688?pwd=R0NRdWhCanNhOThNdStKbHF5dElodz09
Advisor: Prof. Jihoon Seo
Committee Members: Prof. Elizabeth Podlaha-Murphy, Prof. Devon A. Shipp, Prof. Simona Liguori, Prof.
Melissa King