Mechanism of Chemical Mechanical Planarization Induced Edge Corrosion of Copper Line for Cu/Low-$k$ SiOC Interconnects
For complementary metal–oxide–semiconductor (CMOS) technology beyond 90 nm with a very narrow line width, one critical issue is the line edge corrosion in Cu interconnects and the succeeding via process failure. The mechanism of Cu line edge corrosion resulting from the hydrophobic characteristic of low-$k$ SiOC dielectric after the chemical mechanical planarization (CMP) process was studied in detail through the scanning electron microscopy (SEM) analysis and contact angle measurements. The hydrophobic characteristic of low-$k$ dielectric induces a high surface tension that pushes the H2O2 molecules contained in CMP slurry toward the edge of the Cu line, thus enhancing the corrosion reaction. We illustrate the mechanism comprehensively using a schematic model.
- Japanese journal of applied physics. Pt. 1, Regular papers & short notes
Japanese journal of applied physics. Pt. 1, Regular papers & short notes 46(2), 530-535, 2007-02-15
Published by the Japan Society of Applied Physics through the Institute of Pure and Applied Physics