Qualitative model of the magnetron discharge

A simple model of the direct current magnetron discharge is introduced, relating the discharge current I, voltage V, sheath thickness d, plasma density, pressure P  , magnetic field and material constants. The model is based on microscopic physics, balancing the generation and loss of ions. After deriving the balance equation m(d)c(P)VW=1/γ, with m(d) a multiplication factor, c(P) a confinement factor, W the effective ionization potential of the sputter gas and γ the ion induced secondary electron emission coefficient, a generic description of the discharge is made. The model is shown to reproduce many experimental results reported in literature, including a minimum voltage and steep I–V characteristics.