Single-filament effusion cell with reduced thermal gradient for molecular beam epitaxy

Technical Report · Sat Apr 01 04:00:00 EST 1989

OSTI ID:5677635

Streetman, B G

A molecular-beam source utilizing single-filament construction to generate a reproducible and uniform beam of elemental molecules is presented. The filament design is constructed to conform to the shape of pyrolytic boron nitride crucibles utilized in molecular-beam epitaxy (MBE) systems, and to minimize the thermal gradient between the crucible opening and the crucible bottom which is inherent in Knudsen-cell technology. The design also improves heat transfer, efficiency, and flux response of the cell. It is shown that this cell exhibits a better flux response than typical commercially available effusion cells and successfully prevents source material redistribution, thus providing for long-term flux stability and reproducibility in certain materials used in MBE. No increase in background impurity concentration in epitaxial AlGaAs films was observed, when compared to films grown using a standard Varian effusion cell. This cell is currently installed and being used as an aluminum source in a Varian GEN II system.

• Research Organization: Texas Univ., Austin, TX (USA). Microelectronics Research Center
• OSTI ID: 5677635
• Report Number(s): AD-A-209415/9/XAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203 -- Ceramics
Cermets
& Refractories-- Mechanical Properties
360601 -- Other Materials-- Preparation & Manufacture
42 ENGINEERING
420800* -- Engineering-- Electronic Circuits & Devices-- (-1989)
ALUMINIUM ARSENIDES
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
BORON COMPOUNDS
BORON NITRIDES
CHEMICAL REACTIONS
CRUCIBLES
DECOMPOSITION
ENERGY TRANSFER
EPITAXY
FILAMENTS
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
HEAT TRANSFER
IMPURITIES
KNUDSEN GAGES
MEASURING INSTRUMENTS
MOLECULAR BEAM EPITAXY
NITRIDES
NITROGEN COMPOUNDS
PNICTIDES
PRESSURE GAGES
PYROLYSIS
STABILITY
TEMPERATURE GRADIENTS
THERMOCHEMICAL PROCESSES
VACUUM GAGES