ANALYTICAL CHARACTERIZATION OF A PLANAR MAGNETRON RADIO-FREQUENCY GLOW-DISCHARGE SOURCE

The analytical characteristics of a radio frequency (rf) planar magnet ron glow-discharge source were determined with a high-resolution echel le spectrometer. Two sample configurations (both with flat-cathode geo metry) were studied. Smaller samples were mounted on a 5 cm square cop per plate, whereas samples of diameter 2.6 cm or greater were placed d irectly upon the pressure seal. The source was optimized for maximum s ignal. At all pressures (0.05-0.6 Torr) and power levels (10-100 W) st udied here, the precision was detector-readout-noise-limited. The anal yte-emission drift, short-term precision, and detection limits for the source were measured. Warm-up time was around 5-7 min (with a conduct ing cathode), after which the rsd of the signal was 0.29%. The relativ e signal drift was 10% over a 5 min interval during this warm-up time. Detection limits for elements in conducting matrices ranged from 0.04 to 3 ppm, roughly an order of magnitude better than for elements in i nsulating matrices. The shape of the sputtering track was measured in order to determine the viability of the source for depth profiling. (C ) 1997 Elsevier Science B.V.