Ferromagnetic Electrode for Magnetically-Enhanced Plasma Processing System
Original Publication Date: 1988-Aug-01
Included in the Prior Art Database: 2005-Feb-15
In a magnetically-enhanced or directed plasma processing system, the magnetic field lines are controlled to obtain a desired directionality in ion or electron bombardment. Preferably, the magnetic field lines are contoured to impinge upon the substrate surface in a normal direction, thereby causing normal incident bombardment of the charged particles for better profile control, uniformity and sputtering yield. Fig. 1 graphically illustrates the boundary conditions for a static magnetic field between two media when there is no current flow at the boundary. It is known that tan(a2)/tan(a1) = m2/m1 . If region 1 is a gas or vacuum and region 2 is a ferromagnetic material, then m2/m1 = mr, where mr is the relative magnetic permeability.