An Auger Electron Spectrometer (AES) was employed to determine the secondary electron yield of various wall materials. The yield is related to the surface composition which is modified by surface treatments including baking, argon ion etching, exposure to the air, etc. We applied these results to decrease the yield of inner wall of the JT-60 RF waveguides, and showed that the yield monitoring is an effective way for estimating the degree of surface cleaning of the wall materials.
Reactive Atom Beam Etching (RABE) in Cl2 was applied for processing of GaAs. The etch rate was six times higher than that of the conventional ion etching of Ar. Ionized component contained in the beam was less than 11%, so that the fine etching of GaAs could be carried out for both the insulated substrates and the patterned substrates with insulating mask-patterns. Almost perpendicular cross section of side walls was obtained by RABE using photoresist masks. On the other hand, orientation dependent etching (ODE) was obtained by RABE with SiO2 and Al masks.