Self sputtering

There is still the possibility that the metals may be sputtered by multiply charged low-Z impurities such as oxygen and carbon. Self sputtering is also a possibility but at present the question is still to be resolved. Evaporation as a possible source of metal impurities has also been dismissed. Unipolar arcing appeared to be the most likely mechanism leading to the observed impurity level81. ... 

With the exception of sputtering by C+ ions, the physical sputtering of Be and W appears to be well documented. Carbon bombardment, in general, leads to the deposition of protective surface layers (see Sect. 9.2.2). Only in conditions where carbon self-sputtering exceeds unity, i.e., at grazing incidence or at temperatures above 1800 K, could a few yield data points be obtained for clean W surfaces. 

The conditions where net erosion turns into net deposition for carbon irradiation may further be complicated by effects of surface temperature, influencing the self-sputtering yield by radiation-enhanced sublimation (RES) as well as the diffusion and surface segregation of implanted impurities. An example is introduced in Fig. 9.4b, where the erosion of W due to C+ bombardment... 

R. Kukla, T. Krug, R. Ludwig, K. Wilms A Highest Rate Self Sputtering Magnetron Source, Vacuum, 41 (1990) 1968... 

Projectile mass and nature play a role in sputtering yields (especially for molecular species) and surface damage. In a GD there is little choice about the sputtering projectile, although self-sputtering by analyte ions may play a significant role. In SIMS, a wide variety of projectile ion may be used to optimize sensitivity or... 

Self-ion An ion of the vaporized material that can bombard the target on growing film, giving Self-sputtering. See also Film Ion. 

Self-sputtering Sputtering by an ion of the target material being sputtered (Self-ion). See also Film ion. 

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