Particle-in-cell simulations of instabilities in magnetron plasmas.*

Magnetron plasma discharges are typically used in sputtering applications, which require low (\textless 1 Pa) neutral gas pressure. This leads to electron mean free path much larger than device size, demanding a kinetic and non-local description. A popular Particle-in-cell (PIC) method employed for this purpose in its simplest variants (explicit or direct implicit schemes) has certain limitations, which encumber its use for 2d and 3d simulations of realistic cases. A novel energy-conserving implicit PIC technique enables simulations of magnetron plasmas with densities up to those observed in high-power impulse magnetron sputtering (HiPIMS) discharges. The corresponding simulations allow studying a number of pending questions concerning magnetron plasma physics. Of special interest are various instabilities arising in such type of plasmas. Leading to the so-called anomalous transport, for example, through the micro-turbulence or large nonlinearly saturated self-organized spoke structures, they are frequently critical for the discharge mere existence. The present talk will discuss observation of various instabilities in 2d and 3d PIC self-consistent simulations in magnetron discharges operated in different regimes.