Effect of Magnetic Mirror Plasma Confinement on Microwave Electron Cyclotron Resonance/D.C. Discharge for Low Pressure Sputtering(Physics, Process, Instrument & Measurements)
Search this Article
The possibility of using magnetic mirror plasma confinement for microwave electron cyclotron resonance (ECR) plasma enhanced low pressure sputtering is studied. A hollow cylindrical cathode with a target is in the plane of symmetry of the magnetic mirror trap. Two features of the magnetic field axial distribution are important for good operation of the combined ECR/d.c. discharge with mirror confinement. The target current is maximum when the region of plasma generation, the ECR zone, is closer than 10cm fromm the center of the cathode. The mirror ratio has to be higher than 2.5, otherwise the discharge is not self-sustained for simultaneously large microwave power and target voltage. The substrate holder at the chamber axis, when electrically floating or negatively biased, improves the plasma confinement. Plasma density of about 10^<11>cm^<-3>, electron temperature 20eV and plasma potential 50V are measured by a plane Langmuir probe for microwave power 200W, pressure 5×10^<-3>Pa and zero cathode voltage.
- Transactions of JWRI
Transactions of JWRI 24(2), 11-16, 1995-12