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Retarding field energy analyser ion current calibration and transmission

Biomedical Sciences Research Institute Computer Science Research Institute Environmental Sciences Research Institute Nanotechnology & Advanced Materials Research Institute

Denieffe, K, Mahony, CMO, Maguire, PD, Gahan, D and Hopkins, M B (2011) Retarding field energy analyser ion current calibration and transmission. Journal of Physics D: Applied Physics, 44 (075205). [Journal article]

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DOI: 10.1088/0022-3727/44/7/075205

Abstract

Accurate measurement of ion current density and ion energy distributions (IEDs) is oftencritical for plasma processes in both industrial and research settings. Retarding field energyanalysers (RFEAs) have been used to measure IEDs because they are considered accurate,relatively simple and cost effective. However, their usage for critical measurement of ioncurrent density is less common due to difficulties in estimating the proportion of incident ioncurrent reaching the current collector through the RFEA retarding grids. In this paper anRFEA has been calibrated to measure ion current density from an ion beam at pressuresranging from 0.5 to 50.0mTorr. A unique method is presented where the currents generated ateach of the retarding grids and the RFEA upper face are measured separately, allowing thereduction in ion current to be monitored and accounted for at each stage of ion transit to thecollector. From these I–V measurements a physical model is described. Subsequently, amathematical description is extracted which includes parameters to account for gridtransmissions, upper face secondary electron emission and collisionality. Pressure-dependentcalibration factors can be calculated from least mean square best fits of the collector current tothe model allowing quantitative measurement of ion current density.

Item Type:Journal article
Faculties and Schools:Faculty of Computing & Engineering
Faculty of Computing & Engineering > School of Engineering
Research Institutes and Groups:Engineering Research Institute
Engineering Research Institute > Nanotechnology & Integrated BioEngineering Centre (NIBEC)
ID Code:17640
Deposited By:Dr Charles Mahony
Deposited On:29 Mar 2011 11:47
Last Modified:15 Aug 2011 08:49

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