An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Development of a Triplasmatron Ion Source for the Generation of SF5+ and F- Primary Ion Beams on an Ion Microscope Secondary Ion Mass Spectrometry Instrument
Published
Author(s)
John G. Gillen, R L. King, F Chmara
Abstract
A hot filament duoplasmatron ion source operating with argon has been modified by addition of an enclosed expansion cup mounted to the extraction side of the duoplasmatron anode. Using sulfur hexafluoride (SF6) as a feed gas, this triplasmatron ion source has been used to generate SF5+ and F primary ion beams for secondary ion mass spectrometry (SIMS). For positive primary ions, the current extracted from the source is composed of a series of SFx+ cluster ions (x=1-5) with the SF5+ ion being the most intense. SF5+ currents of ~ 10-20 nA with a maximum of 40 nA are obtained at an extraction voltage of 10 kV. By applying a positive bias to the expansion cup, a localized secondary arc discharge is initiated giving 200 nA -300 nA of SF5+ with a current density of 0.5 mA/cm2. Depending on the operating parameters of the source, lifetimes of greater than 70 h have been achieved. For negative primary ions (with the cup removed), the current extracted from the source is primarily composed of F ions with a maximum current of 3 A. The source can be briefly dosed with SF6 and will generate F beams for 1 2 days without any additional gas being added. Evaluation of the SF5+ and F ion beams for common SIMS applications demonstrates that these novel primary beams offer significant advantages for depth profiling, organic surface characterization and imaging.
Citation
Journal of Vacuum Science and Technology
Volume
17
Pub Type
Journals
Keywords
duoplasmatron, ion source, secondary ion mass spectrometry, sulfur hexafluoride, triplasmatron
Gillen, J.
, King, R.
and Chmara, F.
(1999),
Development of a Triplasmatron Ion Source for the Generation of SF<sub>5</sub>+ and F- Primary Ion Beams on an Ion Microscope Secondary Ion Mass Spectrometry Instrument, Journal of Vacuum Science and Technology
(Accessed December 6, 2024)