The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 22, 2008
Filed:
Jul. 13, 2004
Loren N. Pfeiffer, Harding Township, Morris County, NJ (US);
Kenneth William West, Mendham Township, Morris County, NJ (US);
Loren N. Pfeiffer, Harding Township, Morris County, NJ (US);
Kenneth William West, Mendham Township, Morris County, NJ (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
An MBE effusion cell is configured to produce an inverted temperature gradient; that is, the top surface of the melt is not cooler than the bottom surface of the melt. In one embodiment, the MBE effusion cell comprises a crucible having tip, central and base regions. First filaments are located laterally adjacent the tip region; second filaments are located laterally adjacent the central region; and third filaments are located laterally adjacent all three of the regions. The radial density of the number of the heater filaments is lower adjacent the base region than adjacent the tip or central regions. In another embodiment, further tailoring of the inverted temperature gradient is obtained by reducing the amount of insulation at the base of the crucible. In another embodiment, at least one heater filament extends substantially along the longitudinal axis of the crucible and is located adjacent its lateral wall. Dielectric annular spacers are located around the lateral wall and are distributed along the longitudinal axis. The spacers having a multiplicity of holes through which the filaments pass. The filaments and spacers are located within a gas-blocking enclosure.