YPS Schottky Thermal Field Emission Sources

Overview

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 the 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 at 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.

YPS Schottky TFE sources

YPS supplies standard designs, refurbishes legacy designs and supplies custom TFE sources. These products are aimed to customers who are comfortable with changing field emission sources and know how to change, load and align the TFE sources in a clean environment. Operating vacuum for Schottky TFE sources is typically better than 1x10-9mbar. This is higher than the operating vacuum for tungsten or Lab6 sources, but less stringent than for cold field emission sources. The YPS Schottky thermal field emission sources exhibit excellent stability over a wide range of acceleration voltages and long operating times.

YPS-174 Standard Schottky TFE emitter module

The YPS-174 Schottky TFE module is a drop-in replacement for the most common standard Schottky thermal field emitter module. It is equivalent in dimensions with both Denka and FEI standard Schottky field emission cathodes. The suppressor aperture has a diameter of 400µm. The emitter typically protrudes 250µm from the suppressor electrode. The YPS-174 is compatible with thermal field emission sources used on E-beam systems from AmRay, Hitachi, JEOL, ZEISS, LEO, Philips, PHI and Riber.

YPS-184 Schottky TFE emitter module

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 andTescan FE columns. It can also be found on other systems using an electron beam column with TFE source.

YPS exchange Schottky TFE module assemblies for FEI FEG and Sirion SFEG

The YPS FEI FEG and SFEG Schottky TFE module is a complete exchange module assembly replacement for the FEI TFE module used in the FEI XL-30, Sirion, Inspect and Nova NanoSEM systems. The FEG or SFEG emitter module is supplied within the gun assembly and is factory pre-aligned. It is available for the FEI systems units the FEG TFE module assembly and for the SFEG Sirion module assembly. This is available as a complete gun module exchange only. The complete TFE gun assembly will be shipped under inert nitrogen gas with a protective container mounted on the gun assembly flange. The type of TFE source can be identified through the silver label on the gun assembly flange.

• * For exchange only, the original suppressor parts are re-furbished, cleaned and furnished with a new TFE tip
• ** The 184 type TFE emitter module can also be found on other electron beam systems. Contact us for replacement.
• *** YPS-174 Schottky TFE emitter modules for Hitachi FESEMS, Hitachi CD-SEMs and JEOL FESEMs are only compatible with Hitachi and JEOL FESEMs which use a thermal field emitter. Cold field emitters are not compatible with the YPS-174 or YPS-184 modules.