Cathodic etching in a magnetic field

Abstract

In cathodic etching by ion bombardment, we find ourselves concerned with several problems. One of these is the temperature of the specimen. In the absence of effective cooling the temperature rise can be quite large. At 6 W/cm² on the specimen in a particular experimental arrangement patterned after those of other investigators such as Padden and Cain, and Bierlein and Mastel, the author has observed a temperature rise of 700° C. Merely permitting the small specimen to rest on a water-cooled base does not always eliminate the rise; it is necessary to clamp it to the base to reduce the rise to a few degrees. The ion bombardment power is large because of the current-voltage characteristic of the glow discharge — it required about 2 kV to obtain 20 mA at an argon pressure of about 75 μ.