Measurements of characteristic transients of planar electrostatic probes in cold plasmas

Abstract

This article describes how to extract accurate information about a plasma from a capacitively coupled planar probe that is biased using pulsed radio-frequency excitation. The conditions necessary to observe correct saturation of the probe current are investigated, particularly the use of correct geometry and biasing for the guard ring. With these precautions the probe is an effective diagnostic for electron tail temperature at energies beyond those probed by conventional cylindrical probes. The dynamic response of the probe is investigated using conventional sweep voltages and shows the onset of displacement current and inertial effects associated with ions and electrons. In addition the effect of insulating films on the probe surface is examined, showing how the probe continues to operate even when it is coated. Characteristic changes caused by the presence of an insulating film give information about its electrical properties and its thickness.

Patterning of silicon nitride for CMOS gate spacer technology. III. Investigation of synchronously pulsed CH3F/O2/He plasmas

“…This diagnostic technique for CW and pulsed plasmas has been described elsewhere. 22,23 Briefly, a 1 cm 2 planar probe surrounded by a 1 cm 2 guard ring is fed by 10 MHz RF bursts through blocking capacitors; this frequency is chosen to provide effective self-bias of the probe independent of other RF supplies associated with source excitation. Note that to avoid confusion with the pulsed source and bias previously described, the signals applied to the ion flux probe are referred to as "RF bursts."…”

Silicon etching in a pulsed HBr/O2 plasma. I. Ion flux and energy analysis

“…In this study, a planar ion flux probe (IFP), developed by Braithwaite et al 16 and Booth et al 17 and recently adapted to pulsed plasma measurements, 25 was used to directly measure the ion flux onto its surface. In this study, a planar ion flux probe (IFP), developed by Braithwaite et al 16 and Booth et al 17 and recently adapted to pulsed plasma measurements, 25 was used to directly measure the ion flux onto its surface.…”

“…The first one is a capacitively coupled RF probe 16,17 that measures the ion flux at the reactor walls. The first one is a capacitively coupled RF probe 16,17 that measures the ion flux at the reactor walls.…”

Measurement and modeling of time- and spatial-resolved wafer surface temperature in inductively coupled plasmas

“…With the sheath thickness near the probe being less than 1 mm, 19 the guard ring dimension is proper to suppress the edge effects. 20 An Ocean Optics PC2000-UV-VIS-ISA OES is used to monitor the plasma in this study. The optical emission from the plasma is collected, using a focusing lens 13 mm in diameter, from a port located at the chamber sidewall, 2.5 cm above the wafer surface.…”