Abstract

Apparatus for radio frequency sputtering in the megahertz range, primarily higher than about six megahertz, in which the target and anode electrodes are at a low input impedance reactively such that the transfer of power to the target for practical sputtering is normally difficult. The useful plasma which provides the sputtering action has an effective high impedance which obtains between the electrodes during the sputtering process, this high impedance being shunted by a capacitive reactance made up of parasitic paths and similar capacitive components.A string of at least three resonant networks is arranged between the high frequency r.f. source and the sputtering electrodes and these networks transform impedance and voltage from one end of the string at the source to different values and conditions at the other end of the string where they are tied to the electrodes in order to achieve a maximum of overall power transfer efficiency.The invention provides for tuning of the networks, matching of the impedances and variations of circuitry to achieve the desired ends for different types of sputtering target configurations.

Other References

• G N. Jackson, Electrical Characterizations of Double Electrode RF Sputtering Systems, Parts I and II, Vacuum, vol. 21, No. 11, pp. 533-543
• J. S. Logan et al., Electrical Characterization of RF Sputtering Gas Dicharge, Journal of Vac. Sci. and Tech., vol. 6, No. 1, pp. 120-123.