Enhanced Sputtering Process
Original Publication Date: 1979-Aug-01
Included in the Prior Art Database: 2005-Feb-20
During generation of negative ions by ion bombardment of some rare earth (Au and Pt) surfaces, it was discovered that lowering the target temperature below room temperature (i.e., liquid nitrogen as a target coolant) always increased the DC current over otherwise identical conditions if the target were run water cooled. The current density of the liquid-nitrogen-cooled target is about 40% higher than the watercooled target. During negative ion work, the observed result with increased target current density is that the substrates etch at target voltages at which deposition previously prevailed primarily. This indicates an apparent increase in the negative ion yield.