Megasonic cleaning, cavitation, and substrate damage

An atomistic approach

Vivek Kapila, Pierre A Deymier, Hrishikesh Shende, Viraj Pandit, Srini Raghavan, Florence O. Eschbach

Research output: Chapter in Book/Report/Conference proceedingConference contribution

25 Citations (Scopus)

Abstract

Megasonic cleaning has been a traditional approach for the cleaning of photomasks. Its feasibility as a damage free approach to sub 50 nm particulate removal is under investigation for the cleaning of optical and EUV photomasks. Two major mechanisms are active in a megasonic system, namely, acoustic streaming and acoustic cavitation. Acoustic streaming is instrumental in contaminant removal via application of drag force and rolling of particles, while cavitation may dislodge particles by the release of large energy during cavity implosion or by acting as a secondary source of microstreaming. Often times, the structures (substrates with or without patterns) subjected to megasonic cleaning show evidence of damage. This is one of the impediments in the implementation of megasonic technology for 45 nm and future technology nodes. Prior work suggests that acoustic streaming does not lead to sufficiently strong forces to cause damage to the substrates or patterns. However, current knowledge of the effects of cavitation on cleaning and damage can be described, at best, as speculative. Recent experiments suggest existence of a cavity size and energy distributions in megasonic systems that may be responsible for cleaning and damage. In the current work, we develop a two-dimensional atomistic model to study such multibubble cavitation phenomena. The model consists of a Lennard-Jones liquid which is subjected to sinusoidal pressure changes leading to the formation of cavitation bubbles. The current work reports on the effects of pressure amplitude (megasonic power) and frequency on cavity size distributions in vaporous and gaseous cavitation. The findings of the work highlight the role of multibubble cavitation as cleaning and damage mechanism in megasonic cleaning.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
Volume6283 II
DOIs
StatePublished - 2006
EventPhotomask and Next-Generation Lithography Mask Technology XIII - Yokohama, Japan
Duration: Apr 18 2006Apr 20 2006

Other

OtherPhotomask and Next-Generation Lithography Mask Technology XIII
CountryJapan
CityYokohama
Period4/18/064/20/06

Fingerprint

cavitation flow
Cavitation
cleaning
Cleaning
damage
Acoustic streaming
Substrates
acoustic streaming
Photomasks
photomasks
gaseous cavitation
cavities
implosions
two dimensional models
Bubbles (in fluids)
particulates
drag
contaminants
Drag
energy distribution

Keywords

  • Cavitation
  • Megasonics
  • Photomask cleaning

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Kapila, V., Deymier, P. A., Shende, H., Pandit, V., Raghavan, S., & Eschbach, F. O. (2006). Megasonic cleaning, cavitation, and substrate damage: An atomistic approach. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 6283 II). [628324] https://doi.org/10.1117/12.681771

Megasonic cleaning, cavitation, and substrate damage : An atomistic approach. / Kapila, Vivek; Deymier, Pierre A; Shende, Hrishikesh; Pandit, Viraj; Raghavan, Srini; Eschbach, Florence O.

Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6283 II 2006. 628324.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Kapila, V, Deymier, PA, Shende, H, Pandit, V, Raghavan, S & Eschbach, FO 2006, Megasonic cleaning, cavitation, and substrate damage: An atomistic approach. in Proceedings of SPIE - The International Society for Optical Engineering. vol. 6283 II, 628324, Photomask and Next-Generation Lithography Mask Technology XIII, Yokohama, Japan, 4/18/06. https://doi.org/10.1117/12.681771
Kapila V, Deymier PA, Shende H, Pandit V, Raghavan S, Eschbach FO. Megasonic cleaning, cavitation, and substrate damage: An atomistic approach. In Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6283 II. 2006. 628324 https://doi.org/10.1117/12.681771
Kapila, Vivek ; Deymier, Pierre A ; Shende, Hrishikesh ; Pandit, Viraj ; Raghavan, Srini ; Eschbach, Florence O. / Megasonic cleaning, cavitation, and substrate damage : An atomistic approach. Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6283 II 2006.
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