Redeposition of Sputtered Material in a Glow-Discharge Lamp Measured by Means of an Ion Microprobe Mass Analyser

Abstract

The redeposition of sputtered material on the target in a Grimm-type glow-discharge lamp was studied by means of an ion microprobe mass analyser (IMMA) using 16O2+ ions as bombarding species. The target was an aluminium disc with a cylindrical copper insertion, one mm in diameter. The lamp was operated at currents of 50 mA and 100 mA and a voltage of 1200 V. It is estimated that 17% of the copper atoms sputtered are redeposited and may be resputtered.

Emergence and consequences of lateral sample heterogeneity in glow discharge spectrometry

“…41 Enrichment of slower-sputtering material from one region could also retard the sputtering rate elsewhere because of redeposition of the slower-sputtering species. 33 In Figure 4A, the edge of the brass zone is rounded where it meets the Figure 6B shows granular structure evident in an alloy (brass) that can emerge through the sputtering process. This granularity is not due simply to the alloying of the material; the silver surface (which comes from a 99% pure silver wire) shown in Figure 6E also shows a very granular structure that appears to be comprised of large spherical particles of silver within the Ag wire inclusion.…”

“…The selection of iron and carbon in Figure 2 is representative of graphitized cast iron, a material that is expected to exhibit microscopic heterogeneity and mimics the samples described by Weiss. 8 Iron (white pixels in Additionally, atoms ejected from a sample surface are not necessarily those that are directly impacted by the incident species, and the arrangement of the impacted surface could change as the result of redeposition 33 and surface mixing 28 . When an incident ion or neutral atom strikes the surface, it sets off a collisional cascade, resulting in ejection of a nearby atom when the energy from the impact event (or series of events) is greater than the atom binding energy.…”

“…Thus, any rearrangement on the surface will have little net effect, so the signal and related sputtering rate should remain representative of the localized region. Redeposition has been studied experimentally by means of a large heterogeneity (a copper insertion) in an aluminum substrate) 33. In those experiments, sputtered copper from the inclusion redeposited across the sample and in time an equilibrium was established between redeposited and resputtered atoms.However, this equilibrium then did not accurately reflect the true elemental composition of the surface.…”

Radio-frequency microplasmas with energies suited to in situ selective cleaning of surface adsorbates in ion microtraps

“…In doing so, this requires calculation of s -+ He He [28,48] where N a is the adsorbate surface density and σ a is the sputtering cross-section calculated following the approach of [49,50]. Note that a limitation of this approach is that it does not take into account redeposition of the sputtered material through processes such as back-diffusion and back-scattering [51,52]. Solving equation (28…”

Influence of polycrystalline material on crater shape optimization and roughness using low-power/low-pressure direct-current glow discharge mass spectrometry

“…Further, Ferreira and Büger demonstrated copper redeposition during a sputtering process using a glow discharge lamp through copper ion micrographs, which were generated from an ion microprobe mass analyser. 20 It should be noted that these authors also sputtered redeposited material. After a short period of time an equilibrium between simultaneously occurring events of sputtering and redeposition was occurring.…”