MAGNETRON PLASMAS FOR LARGE-AREA UNIFORM SPUTTERING

A new magnetron plasma with multi-targets has been investigated for large-area uniform sputter-coating with uniform erosion of all targets. When the electron Hall parameter was larger than unity and the length of the cathode dark thickness was shorter than the gap length for the applied magnetic flux density B > B-c(mT)=150/d(mm), the discharge was transferred to magnetron mode. In the magnetron mode, it was found that the current density J(d) On the target was approximately proportional to B-2, P-2 and V-3/2, respectively. Here P and V are gas pressure and discharge voltage, respectively. The cathode fall depth was roughly proportional to B-1. From these experimental results and from the numerical analysis for the secondary electrons emitted from the targets, a new expression for the Child-Langmuir law in a magnetized plasma was obtained, in which the sheath thickness was replaced by the equivalent electron Larmor radius.