Monitoring Ion Current and Ion Energy During Plasma Processing Using Radio-Frequency Current and Voltage Measurements

Published

February 1, 2001

Author(s)

Mark A. Sobolewski

Abstract

To obtain optimal results from plasma processing, the energy of ions incident on the substrate and their current or flux must be carefullymonitored and controlled. Although several common diagnostic techniques can be used to measure ion current and ion energy, these techniques areusually not compatible with the processes and reactors used by industry. Methods have been proposed for determining ion properties from the applied rf current and voltage, which are easily measured in commercial reactors. However, such methods are often inaccurate because they rely on false or untested assumptions. Here, a new, more accurate method is presented which makes use of a complete model of the time-dependent ion dynamics in the plasma sheath. The model was validated by comparison to measurements for high-density discharges in an inductively coupled GEC Reference Cell. Measurements were performed for argon discharges at pressures of 1.33 Pa (10 mTorr) for inductive source powers up to 370 W, rf bias powers up to 150 W, and rf bias frequencies of 1 MHz to 10 MHz. Comparisons with previous techniques for monitoring ion current and ion energy show the improvement in accuracy obtained by the new technique.

Proceedings Title

International Conference on the Characterization and Metrology for ULSI Technology 2000 | | AIP Conference Proceedings #550 Characterization and Metrology for ULSI Technology 2000: International Conference | AIP

Volume

550

Conference Dates

June 26-29, 2000

Conference Title

AIP Conference Proceedings

Pub Type

Conferences

Keywords

current, electrical measurements, energy, flux, ion, plasma processing, process monitoring, radio-frequency

Citation

Sobolewski, M. (2001), Monitoring Ion Current and Ion Energy During Plasma Processing Using Radio-Frequency Current and Voltage Measurements, International Conference on the Characterization and Metrology for ULSI Technology 2000 | | AIP Conference Proceedings #550 Characterization and Metrology for ULSI Technology 2000: International Conference | AIP (Accessed December 30, 2024)