Recapture of secondary electrons by the target in a DC planar magnetron discharge

Modelling of Magnetron Sputtering of Tungsten Oxide with Reactive Gas Pulsing

“…The voltage provides indirect information on the present state of the target, but was not included in our previous models. The extension we suggest here is similar to an approach proposed by Buyle et al [14] He attributed changes in the target voltage mainly to the variation of the secondary electron (SE) coefficient which in turn affects the voltage required to sustain the discharge. The discharge voltage is assumed to be indirectly proportional to the g SE , total SE yield of the target surface.…”

Drifting localization of ionization runaway: Unraveling the nature of anomalous transport in high power impulse magnetron sputtering

“…Depending on the emission conditions, and especially on the tilt of the local magnetic field relative to the target surface, secondary electrons are either immediately recaptured by the target 38 or they can escape. Escaping electrons pickup substantial kinetic energy (corresponding to about 90% of the applied voltage) as they cross the sheath.…”

Localized heating of electrons in ionization zones: Going beyond the Penning-Thornton paradigm in magnetron sputtering

“…Penning 6 suggested that while the yield SE γ is reduced by recapture it could still be sufficiently high for three reasons: (i) surface roughness of the cathode, (ii) the magnetic field vector has in most locations a tilt relative to the target surface, and (iii) the SE collides with other particles while completing its first half-gyration. Buyle and coworkers 7 analyzed the situation and they came to the conclusions that the recapture probability recap p is determined by the mean free path of the SE and the average distance travelled before recapture occurs. Since the tilt angle ϑ of the magnetic field relative to the target surface depends on location, the recapture probability …”