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Detection of Chamber Conditioning Through Optical Emission and Impedance MeasurementsDuring oxide etch processes, buildup of fluorocarbon residues on reactor sidewalls can cause run-to-run drift and will necessitate some time for conditioning and seasoning of the reactor. Though diagnostics can be applied to study and understand these phenomena, many of them are not practical for use in an industrial reactor. For instance, measurements of ion fluxes and energy by mass spectrometry show that the buildup of insulating fluorocarbon films on the reactor surface will cause a shift in both ion energy and current in an argon plasma. However, such a device cannot be easily integrated into a processing system. The shift in ion energy and flux will be accompanied by an increase in the capacitance of the plasma sheath. The shift in sheath capacitance can be easily measured by a common commercially available impedance probe placed on the inductive coil. A buildup of film on the chamber wall is expected to affect the production of fluorocarbon radicals, and thus the presence of such species in the optical emission spectrum of the plasma can be monitored as well. These two techniques are employed on a GEC (Gaseous Electronics Conference) Reference Cell to assess the validity of optical emission and impedance monitoring as a metric of chamber conditioning. These techniques are applied to experimental runs with CHF3 and CHF3/O2/Ar plasmas, with intermediate monitoring of pure argon plasmas as a reference case for chamber conditions.
Document ID
20010106505
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Cruden, Brett A.
(Eloret Corp. Moffett Field, CA United States)
Rao, M. V. V. S.
(Eloret Corp. Moffett Field, CA United States)
Sharma, Surendra P.
(NASA Ames Research Center Moffett Field, CA United States)
Meyyappan, Meyya
(NASA Ames Research Center Moffett Field, CA United States)
Date Acquired
August 20, 2013
Publication Date
February 5, 2001
Subject Category
Nuclear Physics
Meeting Information
Meeting: American Vacuum Society Conference and Microelectronics and Interfaces
Location: Santa Clara, CA
Country: United States
Start Date: February 5, 2001
End Date: February 9, 2001
Sponsors: American Vacuum Society
Funding Number(s)
PROJECT: RTOP 632-62-00
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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