Novel Analytical Method for Improving the Megasonic Extraction Efficiency of Etch Chamber Components Surfaces as Determined by Single Nanoparticle- Inductively Coupled Plasma-Mass Spectrometry (sNP-ICP-MS)
ABSTRACT
Nanoparticles (1-100 nm) are naturally present in all aspects of the chip fabrication process. The wet or dry etching processes in the chamber often create nanoparticle (NP) contaminants that cause chip defects and ""random yield loss"". Current analytical metrology must satisfy the demands of the semiconductor industry for the detection of particles down to sub-5 nm levels. In this study, chemical extractants (e.g. SC-1) for improving megasonic NP extraction efficiency on coupon surfaces will be evaluated and the NP data will be presented and compared to NP data for Ultra Pure Water (UPW) extractant.
In contrast to traditional ICP-MS, which is used to determine only the trace concentration levels of dissolved elements, sNP-ICP-MS incorporates shorter dwell times allowing individual elemental nanoparticle events to be detected (Figure 1). The frequency of NP pulse represents the concentration of elemental NPs in the sample, and the pulse intensity is proportional to the mass of the element or the particle size by the assumption of a spherical NP shape. Consequently, sNP-ICP-MS, unlike traditional ICP-MS, can provide multiple figures of merit including elemental particle concentration, particle size distribution and median and mean NP information. This technique has been successfully used to determine NPs in UPW, chemicals and etch part extracts [1].
Megasonic extraction, owing to its high frequency, gentle acoustic energy and controlled cavitation was previously determined by a validated sNP-ICP-MS method [1] to be the optimal extraction method for the removal of NPs from etch coupon surfaces. Two etch coupon (Aluminum alloy and quartz) surfaces were extracted by megasonic energy with UPW as the extraction medium. The extraction efficiency of multiple megasonic cleans of the surface, varied for each coupon, due to the varying chemistries of the surfaces and the competing forces between the NPs and the substrates. Exploring chemical extractants such as SC-1 may improve extraction efficiencies and overcome these challenges.
[1] Mey-Ami L, and Li, F. J. Vac. Sci. Technol. A 43, 043206 (2025).
BIOGRAPHY
Dr. Lisa Mey-Ami is a Senior Scientist and Technical Community Leader within the R&D group at Air Liquide Balazs in Fremont, CA. She specializes in the innovation and optimization of advanced analytical methodologies designed to push the boundaries of elemental detection limits and metrology across diverse matrices and various analytical techniques.
Dr. Mey-Ami has developed and published novel, state-of-the-art methods for the detection and characterization of nanoparticles in water, chemical reagents, and etch part surfaces. Her work leverages single nanoparticle Inductively Coupled Plasma Mass Spectrometry (sNP-ICP-MS) to provide critical information on elemental nanoparticle size distribution and particle concentration, driving significant advancements in contamination control for the microelectronics industry.