Microstructure and Pattern Size Dependence of Copper Corrosion in Submicron-Scale Features

Abstract

The effects of grain size and pattern geometry on the etching rate were investigated by using our invented pattern, and each pattern has a same height of electrodeposits regardless of pattern size after electroplating. It was found out that the logarithmic value of the etching rate is inversely linear with the pattern width at self-annealed specimen. In other words, as the pattern width decreases, the etching rate increases exponentially. Such tendency of the etching rate is owing to the result that the interfacial energies of pattern surface and grain boundary per unit volume increase by the decrease of pattern width. In contrast, the as-deposited sample shows a flat etching rate for pattern sizes. In addition, at the narrow patterns with a pattern width of below 220 nm, the etching rate in the nanocrystalline structure of the as-deposited sample is lower than in the grain grown structure of the self-annealed sample. It can be surmised that the stresses caused by interfacial energies may be relaxed by the nanocrystalline structure in the as-deposited sample.

Nucleation and Growth Behaviors of Pd Catalyst and Electroless Ni Deposition on Cu (111) Surface

“…6. [17][18][19][20][21] Figure 7 shows the high resolution transmission electron microscopy (TEM) image for the sample of Ni 2 s/Pd 30 s, and it was reconfirmed that the Pd nuclei had a size of about 3 ∼ 5 nm. We could discern the lattice fringes of the Cu (111), Ni (111), and Pd (111) planes by their interplanar spacings of 0.2083, 0.2031, and 0.2242 nm, respectively.…”

Multilayer Laminated Copper Electrodeposits and Their Mechanical Properties

“…A geometric constraint in the patterned space is expected to affect the grain growth behavior. [3][4][5] It has been reported that when microstructures of different sizes are formed depending on geometrical constraints in the pattern space, electrochemical reaction characteristics, such as galvanic corrosion are also affected. 5 In addition, Janus Green B (JGB), one of the levelers used to suppress bump formation by the curvature enhanced accelerator coverage (CEAC) phenomenon of the plating accelerator, is adsorbed on the surface of the electrodeposits resulting into co-deposition inside the electrodeposits.…”

“…[3][4][5] It has been reported that when microstructures of different sizes are formed depending on geometrical constraints in the pattern space, electrochemical reaction characteristics, such as galvanic corrosion are also affected. 5 In addition, Janus Green B (JGB), one of the levelers used to suppress bump formation by the curvature enhanced accelerator coverage (CEAC) phenomenon of the plating accelerator, is adsorbed on the surface of the electrodeposits resulting into co-deposition inside the electrodeposits. In our previous experiment in which the concentration of JGB was changed from 0 to 1 mM, it was found that the impurity concentration of the plating layer was proportional to the concentration of JGB added to the plating solution, and recrystallization was suppressed at a concentration of 0.2 mM or more.…”