Cleaning Solution Effect on Electrical and Reliability Properties of Dense and Porous Low Dielectric Constant Materials

• Published in: ECS transactions 2015-04, Vol.66 (6), p.165-176
• Main Authors: Cheng, Yi-Lung, Huang, Chi-Jia
• Format: Article
• Language: English
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/06606.0165ecst

The effects of different cleaning solutions and various immersion times on the physical, electrical, and reliability characteristics of dense and porous low-k dielectric films were investigated in this study. After immersing into a wet cleaning solution, both low-k dielectric films are needed to remove the physically-adsorbed water by a post-baking process in order to ensure a better performance. The experimental results indicated that irrespective of acid HF and basic NH4OH solutions, they would cause negative impacts on the low-k films, even performing a post-baking process due to the existence of chemically-bonded moisture. The formation of chemically-adsorbed moisture was serious for the porous low-k dielectric films in the NH4OH solution. In addition to the adsorbed moisture, the HF solution caused the low-k dielectric's structure and porosity to be modified and its impact increased with the immersion time. Except the positive benefit in reducing the dielectric constant, these changes caused the degradation in electrical and reliability performance for low-k dielectric films.