Single Filament Source
3Pages

Single Filament Source • Patented design with over 600 in the field • Single filament “cold-lip” and “hot-lip” designs • Compatible with virtually all power supplies • Wide range of sizes available • Available as a direct replacement for most MBE systems • Excellent performance and value Description Veeco MBE Single Filament Sources are available in three versions: • Standard Filament Source. The Standard Filament Source is a general purpose source featuring a single uniformly distributed heater filament. All designs include a band thermocouple with a large crucible contact area. Although source heating is uniform, the source is slightly cooler at the tip due to radiative heat loss at the crucible orifice, especially for the larger capacity sources. For evaporation of aluminum, it may be desirable to enhance this “cold-lip” effect as discussed below. • Modified Filament Source. This source features a patented “modified” single filament design. “Hot-lip” heating is achieved with one filament which uniformly heats the bottom portion of the crucible but includes extra filament density at the top to compensate for radiative heat loss at the orifice. This design is particularly effective with smaller capacity crucibles. • Cold-Lip Source for Aluminum. Molten aluminum wets PBN, often resulting in charge creep and overflow in conventional sources. Factors contributing to aluminum overflow include source installation angle, amount of aluminum loaded, and source ramp rates. Users observing persistent creep and overflow problems with standard sources may require a special single filament source with a shorter filament that produces an exaggerated “cold lip.” The Cold-Lip Source for Aluminum promotes freezing of aluminum at the crucible lip before it can creep out and damage the source. For demanding applications, or when large source capacities are required, Dual Filament or SUMO® Sources are recommended. Performance and Benefits Single Filament Sources offer good performance and value for general purpose applications. The Standard Filament Source provides better accuracy and stability due to the band-style thermocouple leading to increased thermal stability. The hot-lip heating in a Modified Filament Source reduces gallium- and indium-related oval defects. It also improves the stability and reproducibility of evaporation of other materials by preventing condensation in the crucible.

Product Specifications Source Characteristics Charge Materials Standard and Modified Filament Sources are recommended for use with medium vapor pressure materials likely to be evaporated or sublimed at 750-1300°C. The Cold-Lip Source is for use with aluminum only. Crucible Shape Minimum Mounting Flange Size Standard Filament Type Ta wire heater filament, PBN supports Thermocouple Type Standard patented Type C (W/Re 5/26%) band thermocouple In-Vacuum Length Typical Operating Temperature Maximum Outgassing Temperature Power Requirements for Maximum Temperature Single Filament Modified...

Single Filament Source Selection Guide Typical Source Commonly Used Indicated By “X” System 1cc GEN II™ Perkin-Elmer Other Veeco sources are also available for use on systems from Eiko, Anelva, Ulvac, SVTA, and DCA, as well as custom chambers. Please contact Veeco for details. Solutions for a nanoscale world.™ Compound Semiconductor • MBE Operations 4900 Constellation Drive, St. Paul, MN 55127 USA Phone: (651) 482-0800, Fax: (651) 482-0600 www.veeco.com/mbe © 2005 Veeco Instruments Inc. All rights reserved. SUMO is a registered trademark, and GEN II, GEN III, GEN930, GEN20, and Solutions...