Study of mechanical properties of Cu through-silicon-vias (TSV) specimen using electrodeposition bath

The Cu specimens were fabricated by the UV-LIGA process using the electrodeposition bath for through-silicon-via (TSV) filling. Mechanical property of th e Cu specimens was investigated by a uniaxial tensile test. The elastic modulus, yield strength, breaking stre ngth and ultimate strain are 95GPa, 314MPa, 367MPa and 12.4%, respectively. The results indicated that the yield strength and breaking strength of as-deposited Cu specimens were higher than that of the bulk Cu, while the elastic modulus was lower than that of the bulk Cu. The elastic modulus of C u thin film in surface and section are 115.7GPa and 105.4GPa measured by nanoindentation, respectively. This difference is caused by the difference of the grain orientation between the surface and section of Cu thin film.