Design and characterization of a planar magnetron radio-frequency glow discharge source for atomic emission spectrometry

摘要

A planai magnetron radio-frequency-powered glow discharge source has been constructed and characterized Electrical behavior, sputtering rates, and emission properties of the source have been studied with both conducting and insulating samples over a pressure range of 0.05 to 0.6 Torr, and over a forward-powei'range between 30 and 120 W The bias voltage showed little or no dependence on power or on pressure between 0 2 and 0.6 Torr. However, at lower pressures there was a sharp increase in the voltageas pressure was dropped, signaling a change in the operational mode of the discharge. The magnetron source proved to have much higher sputtering rates foi both conducting and insulating samples than a similar source without a magnet; the highest sputtering rates were found at 0.05 Torr. The dependence of emission on pressure was similar to that of previously described d.c magnetron sources. Detection limits ranged from 1 to 50 ppm for elements in a conducting matrix.