Title :
The Effects of Osmium Coating and Chemical Cleaning on SEM Images of Dispenser Cathode Surface Porosity
Author :
Tarter, J.O. ; Roberts, S.
Author_Institution :
Semicon Associates
Abstract :
Most tungsten dispenser cathodes are coated with a thin refractory metal layer to lower the work function and enhance emission. The coating must not interfere with the dispensation of barium from the tungsten matrix onto the emitting surface. Cathode manufacturers and users have long discussed the possible effects of the coating being either too thin or too thick and masking the pores in the tungsten matrix. SEM inspection is often used to evaluate the surface porosity of a dispenser cathode
Keywords :
cathodes; porosity; scanning electron microscopy; sputtered coatings; surface cleaning; work function; chemical cleaning; osmium coating; scanning electron microscopy; surface porosity; tungsten dispenser cathode; work function; Barium; Cathodes; Chemicals; Cleaning; Coatings; Diodes; Inspection; Manufacturing; Radio frequency; Tungsten; Coatings; Dispenser cathode; Porosity; SEM Inspection;
Conference_Titel :
Vacuum Electronics Conference, 2006 held Jointly with 2006 IEEE International Vacuum Electron Sources., IEEE International
Conference_Location :
Monterey, CA
Print_ISBN :
1-4244-0108-9
DOI :
10.1109/IVELEC.2006.1666282
