Angular resolved mass-energy analysis of species emitted from a dc magnetron sputtered NiW-target
Research output: Contribution to journal › Article › Research › peer-review
External Organisational units
- Materials Chemistry, RWTH Aachen
- Erich Schmid Institute of Materials Science
- RWTH Aachen
- PLANSEE SE
A Ni81W19 target was dc sputter eroded at constant target power density from a tiltable magnetron at different Ar pressures. The combination with a stationary mass-energy analyzer allowed investigating the abundance of different species within the plasma as well as the ion energy distribution functions of 40Ar + 58Ni +, and 184W + at any given angle θ between 0° and 90° from the target normal. Ar + ions are detected at θ angles close to the target normal, whereas metal atoms are observed at larger θ angles. Ni is emitted at smaller θ angles compared to W. Both investigated metal ion energy distributions exhibit a high energy tail with energies up to 50 eV. Increasing the Ar pressure first affects the trajectories of Ni before W atoms. This can be understood by considering the smaller mass difference between Ni and Ar compared to W and Ar. This enables more effective energy transfer and larger scattering angles of Ni undergoing collisions with Ar compared to W. Subsequent film depositions on a spherical-shell substrate holder, covering angles between 0° and 80° from the target normal, allowed for a comparison of the angular dependent film- and plasma-compositions. This correlative analysis suggests that selective resputtering of Ni by energetic Ar neutrals, reflected from the target, leads to the observed difference between the target and film composition during sputter deposition from a multielement NiW target.