The Effects of Bath Temperature on the Formation of Nanotwin in Electrodeposited Cu

Abstract

Cu films with high mechanical strength and low electrical resistivity are required in various industrial fields, and nanotwinned Cu is a strong candidate to satisfy these requirements due to its extraordinary microstructures. The formation mechanism and the effect of deposition parameters on the formation of nanotwinned Cu have been intensively investigated. In this research, the effects of bath temperature on the formation of nanotwinned Cu in pulse current electrodeposition is studied. Although the variations in bath temperature are as small as 30 degrees C (from 40 degrees C to 10 degrees C), the tensile strength increased by similar to 56% (479 MPa to 745 MPa) without significant degradation of elongation and electrical conductivity. In addition, an increase in nanotwin density was observed in the sample deposited at low temperature. The diffusion coefficient of Cu+2 ions, overpotential, and residual Cu film stress were measured to investigate the effects of bath temperature.