Modification of Ta/polymeric low-k interface by electron beam treatment

• Main Authors: Prasad, K., Damayanti, M., Gan, Zhenghao, Mhaisalkar, Subodh Gautam, Chen, Zhong, Chen, Zhe, Zhang, Sam, Jiang, Ning
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2012
• Subjects: DRNTU::Engineering::Materials
• Online Access: https://hdl.handle.net/10356/90682; http://hdl.handle.net/10220/7701
• Institution: Nanyang Technological University

Polymeric dielectric, porous polyarylene ether (PAE), was introduced in the Cu damascene structures because of its low dielectric constant to reduce resistance-capacitance (RC) delay. One of the requirements of a low-k material includes its good adhesion to the other interconnect materials. In the present study, the adhesion energy (Gc) of the barrier layer Ta/PAE interface was quantitatively measured by a four-point bending technique. The obtained Gc value of the pristine Ta/PAE interface was 5.9 ± 1.1 J/m2. If the PAE was subjected to electron-beam (EB) treatment with low dose (20 μC/cm2) prior to Ta deposition, Gc value increased to 8.1 ± 0.5 J/m2. However, with high-dose (40 μC/cm2) EB treatment, Gc value reduced to 4.0 ± 0.6 J/m2. The adhesion improvement and degradation induced by low- and high-dose EB were correlated to the increase and reduction of the amount of C–Ta bonds at the Ta/PAE interface, respectively. The phenomena were further studied by X-ray photoelectron spectroscopy analysis.