No abstract

Nanotwinned copper possesses a distinctive structure with higher mechanical strength and stability without compromising on resistivity. This study aimed to characterize the nanomechanical properties along with the scratch hardness of the (111) nanotwinned copper thin film wafer in ambient and slurry conditions by triboindenter. Experiments were performed on Hysitron TI 980 Triboindenter using Berkovich and conical indenter for nanoindentation and nano scratch, respectively. We studied the impact of nanotwinned structures on quasistatic and scratch hardness of copper thin film wafers given the potential applicability of nanotwinned copper thin films as interconnects. CMP was extensively applied to obtain the nanoscale surface finish required in the semiconductor micro-nano fabrication industry. The nanomechanical properties of (111) nanotwinned copper thin film wafer with passivation in polishing slurry conditions were imperative parameters to study the polishing behavior of material. Hardness, Young's modulus, and scratch hardness of the nanotwinned copper thin film specimens were evaluated by nanoindenter in ambient and slurry conditions. Results of this study with characteristic parameters of (111) nanotwinned copper thin film wafer can be further used to estimate the material removal of chemical mechanical polishing for high volume production of IC devices in future work.

In this study, thermal and argon (Ar) plasma/wetting treatments were combined to enhance the bonding strength of polyimide (PI) films. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) was used to analyze the changes in the PI imidization degrees. The contact angles of the PI films were also measured. The results show that the contact angles of the fully cured PI films markedly decreased from 78.54° to 26.05° after the Ar plasma treatments. X-ray photoelectron spectroscopy (XPS) analysis was also conducted on the PI surfaces. We found that the intensities of the C-OH and C-N-H bonds increased from 0% to 13% and 29% to 57%, respectively, after Ar plasma activation. Such increases in the C-OH and C-N-H intensities could be attributed to the generation of dangling bonds and the breakage of the imide ring or polymer long chains. Shear tests were also conducted to characterize the bonding strength of the PI films, which, after being treated with the appropriate parameters of temperature, plasma power, and wetting droplets, was found to be excellent at greater than 35.3 MPa.