Development of atomic radical monitoring probe and its application to spatial distribution measurements of H and O atomic radical densities in radical-based plasma processing

Abstract

Articles you may be interested inThe multipole resonance probe: A concept for simultaneous determination of plasma density, electron temperature, and collision rate in low-pressure plasmas Appl. Phys. Lett. 93, 051502 (2008); 10.1063/1.2966351Floating probe for electron temperature and ion density measurement applicable to processing plasmas Electrostatic probe diagnostics of a planar-type radio-frequency inductively coupled oxygen plasma Atomic radicals such as hydrogen ͑H͒ and oxygen ͑O͒ play important roles in process plasmas. In a previous study, we developed a system for measuring the absolute density of H, O, nitrogen, and carbon atoms in plasmas using vacuum ultraviolet absorption spectroscopy ͑VUVAS͒ with a compact light source using an atmospheric pressure microplasma ͓microdischarge hollow cathode lamp ͑MHCL͔͒. In this study, we developed a monitoring probe for atomic radicals employing the VUVAS with the MHCL. The probe size was 2.7 mm in diameter. Using this probe, only a single port needs to be accessed for radical density measurements. We successfully measured the spatial distribution of the absolute densities of H and O atomic radicals in a radical-based plasma processing system by moving the probe along the radial direction of the chamber. This probe allows convenient analysis of atomic radical densities to be carried out for any type of process plasma at any time. We refer to this probe as a ubiquitous monitoring probe for atomic radicals.

Production and Detection of H Atoms and Vibrationally Excited H2 Molecules in CVD Processes

“…The problem is how to evaluate the spectral profile of the light source, because that is often affected by self‐absorption effects 75. Takashima et al avoided this difficulty by using a high‐pressure microdischarge hollow‐cathode lamp,87 and have succeeded in determining absolute densities in many systems by employing this technique 84, 87–89. One limitation of this approach is the narrow dynamic range.…”

“…Another is the lack of spatial resolution. Information on the column density only can be obtained, unless a special microprobe assembly is used 89. These limitations are common to the vacuum‐UV laser absorption technique, which will be discussed in Section 4.3.1.…”

Surface Loss Probability of Nitrogen Atom on Stainless-Steel in N2Plasma Afterglow

“…Figure 2 shows a schematic diagram of the spatial distribution measurements of the density of N atoms in a remote N 2 plasma using a radical monitoring probe. 36) Only one port was required for the measurements, allowing the spatial distribution to be determined simply by moving along the probe the chamber radius. The measurements were carried out at a position 150 mm from the inductively coupled N 2 plasma (N 2 -ICP).…”

Development of vacuum ultraviolet absorption spectroscopy system for wide measurement range of number density using a dual-tube inductively coupled plasma light source

“…10 Recently, vacuum ultraviolet absorption spectroscopy (VUVAS) that uses a plasma light source has been developed as an approach for direct number density measurement to the ground state. 11,12 Absorption spectroscopy gives an absolute number density from the fractional absorption without any calibration, and it is theoretically applicable to any number density target. 13 However, the measurement error increases drastically for fractional absorption that is smaller than 1% or larger than 99%.…”