Valved Cracker for Phosphorus
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Valved Cracker for Phosphorus Mark V 500cc Valved Cracker for Phosphorus (top) and 5000cc Valved Cracker for Phosphorus (right). • Patented design with more than 175 in the field • Utilizes a nozzle for excellent flux uniformity and reduced material waste • Compatible with high-temperature outgassing • A proven effective solid source alternative to phosphine (PH3) • Vacuum sealed crucible to optimize material quality • Recommended for use with Phosphorus Recovery System for efficient, safe means of phosphorus neutralization Description The patented Valved Cracker for Phosphorus is uniquely tailored to provide a controlled and reproducible P2 flux from a solid phosphorus charge. The multi-zone crucible is designed for in-situ conversion from commercially available red phosphorus to the more reactive white phosphorus with its advantageous evaporation characteristics. Veeco’s unique thermal control system features independent heaters for the red and white phosphorus zones, and an air cooling jacket on the white phosphorus reservoir. Both heaters are used for thorough source outgassing. After loading, efficient charge conversion is achieved by heating the red phosphorus zone to evaporation temperatures, while cooling the white phosphorus reservoir to promote condensation of the P4 vapor. During growth, an adjustable temperature gradient is achieved using just a single bulk heater. With the heater in the red phosphorus zone, the crucible can be heated to a red phosphorus temperature of 190°C (sufficiently low to avoid evaporation of red phosphorus during operation) and a white phosphorus temperature of 75-100°C. Air cooling reduces the temperature in the white zone to the desired operating level. This system provides excellent thermal stability, even at white zone temperatures as low as 65°C. For rapid and reliable flux control, the gas flow is metered from the crucible to the cracking zone with an all-metal needle valve. Efficient conversion of P4 to P2 occurs in the high-conductance cracking zone. Principle of operation for the Phosphorus Valved Cracker. Source material is loaded into the red P crucible. Before growth, the crucible is heated for in-situ conversion to white P. The white P is heated to generate a P4 flux. A needle valve regulates the evaporant flow to the cracking zone. The cracking zone is heated to ensure complete conversion of the flux from P4 to P2.

A Veeco Phosphorus Valved Cracker Temperature Controller is recommended for use with this source, as well as a Veeco SMC-II Automated Valve Positioner for reliable, automated control of the needle valve. In addition, due to white phosphorus’s extreme reactivity with oxygen, Veeco also offers a Phosphorus Control System that ensures an efficient, safe means of trapping and neutralizing white phosphorus prior to venting the MBE system for maintenance and/or source reloading. With recent enhancements, the Mark V Valved Cracker for Arsenic incorporates a nozzle that provides excellent flux...

Product Specifications Source Characteristics Maximum Charge Capacity Minimum Mounting Flange Size Standard 2.75”/70mm With Water-Cooling 4.5”/114mm Standard 6”/152mm With Water-Cooling 6”/152mm In-Vacuum Length Standard 1.41”/36mm With Water-Cooling 2.27”/56mm Standard 2.2”/56mm With Water-Cooling 2.7”/69mm External Dimensions Contact Veeco Crucible Dimensions/Interior Fill Port Diameter Typical Operating Temperatures During Conversion Red Zone White Zone Cracking Zone White Zone Cracking Zone During Evaporation Maximum Outgassing Temperature (Power Requirements) Red Zone White Zone...

Valved Cracker for Phosphorus Selection Guide Typical Source Commonly Used Indicated By “X” System 500cc Perkin-Elmer Other X Veeco sources are also available for use on systems from Eiko, Anelva, Ulvac, SVTA, and DCA, as well as custom chambers. Contact Veeco for details. Innovation. Performance. Brilliant. Veeco Instruments Inc. 4900 Constellation Drive, St. Paul, MN 55127 USA Phone: (651) 482-0800, Fax: (651) 482-0600 www.veeco.com/mbe © 2011 Veeco Instruments Inc. All rights reserved. (2-11) GEN200, GEN2000, GEN II, GEN III, GEN930, GEN10, GEN20 and Veeco are trademarks of Veeco...