title: The Influence of Pulsed Electroplating Frequency and Duty Cycle on Copper Film Microstructure and Stress State.
abstract: In this work we studied the impact of pulse electroplating parameters on the cross-sectional and surface microstructures of blanket copper films using electron backscattering diffraction and x-ray diffraction. The films evaluated were highly (111) textured in the direction perpendicular to the film surface. The degree of preferential orientation was found to decrease with longer pulse on-times, due to strain energy driven growth of other grain orientations. Residual biaxial stresses were also measured in the films and higher pulse frequencies during deposition led to smaller biaxial stresses in the films. Film stress was also found to correlate with the amount of twinning in the copper film cross-sections. This has been attributed to the twins' thermal stability and mechanical properties.
authors.affiliation: Glass Processing and Characterization Laboratory/College of Optics and Photonics, CREOL - University of Central Florida, 4304 Scorpius Street, Orlando, FL 32816, USA; School of Material Science & Engineering, Clemson University, COMSET, 161 Sirrine Hall, Clemson, SC 29634, USA.
authors.forename: James B
authors.initials: JB
authors.lastname: Marro
authors.affiliation: Electron Microscopy Laboratory, Advanced Materials Research Laboratory (AMRL), Clemson University, 91 Technology Drive, Anderson, SC, 29625, USA.
authors.forename: Taghi
authors.initials: T
authors.lastname: Darroudi
authors.affiliation: Engineering Physics Division, National Institute of Standards and Technology (NIST), 100 Bureau Drive, Gaithersburg, MD 20899, USA.
authors.forename: Chukwudi A
authors.initials: CA
authors.lastname: Okoro
authors.affiliation: Engineering Physics Division, National Institute of Standards and Technology (NIST), 100 Bureau Drive, Gaithersburg, MD 20899, USA.
authors.forename: Yaw S
authors.initials: YS
authors.lastname: Obeng
authors.affiliation: Glass Processing and Characterization Laboratory/College of Optics and Photonics, CREOL - University of Central Florida, 4304 Scorpius Street, Orlando, FL 32816, USA; School of Material Science & Engineering, Clemson University, COMSET, 161 Sirrine Hall, Clemson, SC 29634, USA.
authors.forename: Kathleen C
authors.initials: KC
authors.lastname: Richardson
keywords: Copper; Electrodeposition; Microstructure; Stress; Twins