The YPS Schottky type thermal field emission sources are an excellent choice to replace used TFE sources in electron beam systems, including FESEM, SFEG-SEM, FETEM, EPMA, Auger and CD-SEM systems. The YPS sources are drop-in replacements for existing FEI and Denka style sources also known as 184 and 174 type suppressors. The YPS Schottky TFE source consists of a single crystal (100) tungsten wire with a very sharp tip including a zirconium reservoir around the tungsten tip wire. The tip is mounted on a hairpin filament which is used to maintain the tip ate a temperature of around 1800K. This assembly is mounted in a cylindrical suppressor electrode with an aperture through which the sharp tip protrudes. Electrons are emitted from the tip due to both thermal excitation and the electrical field at the tip. The YPS Schottky TFE source tip typically has a radius of 0.3µm and protrudes around 250µm to ensure high brightness of the source.
The YPS-184 Schottky TFE emitter module is a drop-in replacement alternative for the FEI Schottky TFE emitter module. The suppressor aperture has a diameter of 500µm and the emitter protrudes 250µm from the suppressor electrode. The YPS-184 is easy to recognize through the flange at the base. The YPS-184 Schottky TFE module is used in FEI/Philips, CamScan and Tescan FE columns. It can also be found on other systems using an electron beam column with TFE source.