Compact electron cyclotron resonance plasma source optimization for ion beam applications

A prototype electron cyclotron resonance (ECR) plasma source has been designed and developed to deliver a maintenance-free, stable and controllable current ion beam. The plasma source can accommodate both low and high power microwave applicators for different applications. Selection of the optimum magnetic field arrangement and position with respect to the microwave applicator ensures a high density plasma operational at pressures below 5.0 x 10(-2) Pa. From initial tests a plasma density of 5.0 x 10(10) cm(-3), electron temperature of 1.5 eV and a plasma potential of 10 V were measured 10 cm downstream for an input microwave power of 100 . W at an Ar pressure of 0.1 Pa. A saturation ion current density of 2 mA/cm(2) was measured independently using a biased Langmuir probe and results matched well the calculated values. Ion beams with non-uniformity of +/-10% have been used to sputter with control a diamond-like-carbon film with rates of up to 30 nm/h at room temperature.