Plasma-Assisted Cleaning by Electrostatics (PACE)

W. M. Lytle, H. Shin, D. N. Ruzic

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

Abstract

The need for a non-contact contamination removal technique has been exhibited by various companies. While an EUV compatible pellicle is being researched, contamination will become an ongoing problem to overcome. Some techniques that are being considered for contamination removal include the use of Shockwaves which are potentially damaging, as well as rolling contamination off of a surface. Depending on feature size, rolling or moving of contamination horizontally across a surface is limited as there is a strong possibility that the contamination will get trapped in between features. Plasma- Assisted Cleaning by Electrostatics (PACE) is a non-contact removal method that utilizes charge imbalances to remove particles perpendicular to the surface. A positive bias is applied to the top of the sample for conducting samples or to the substrate behind an insulating sample. This positive bias draws in net electrons from the plasma to the entire surface. The contamination charges negatively and the positive bias is removed and switched with a negative bias. The combination of substrate/particle charge imbalance as well as electric field effects from the plasma sheath provide for the removal mechanism. Surface damage has been avoided by staying below the sputtering threshold for the surface materials of the samples. Recent tests on 2.5 nm ruthenium on Si/Quartz using the PACE technique coupled with Atomic Force Microscopy data has shown no roughening of the surface and approximately 90% removal efficiency of contamination. In addition, Auger Electron Spectroscopy scans show no removal of the 2.5 nm ruthenium capping layer. Removal results for 30 nm to 220 nm PSL particles as well as select other contamination materials on samples comparable with EUV masks in addition to damage assessments will be presented.

Original languageEnglish (US)
Title of host publicationMetrology, Inspection, and Process Control for Microlithography XXI
EditionPART 3
DOIs
StatePublished - Oct 15 2007
EventMetrology, Inspection, and Process Control for Microlithography XXI - San Jose, CA, United States
Duration: Feb 26 2007Mar 1 2007

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
NumberPART 3
Volume6518
ISSN (Print)0277-786X

Other

OtherMetrology, Inspection, and Process Control for Microlithography XXI
CountryUnited States
CitySan Jose, CA
Period2/26/073/1/07

Fingerprint

Cleaning
Contamination
Electrostatics
cleaning
contamination
Plasma
electrostatics
Plasmas
Ruthenium
Non-contact
Charge
ruthenium
Substrate
Electron
Plasma sheaths
damage assessment
pellicle
Electric field effects
Damage Assessment
EUV Mask

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Cite this

Lytle, W. M., Shin, H., & Ruzic, D. N. (2007). Plasma-Assisted Cleaning by Electrostatics (PACE). In Metrology, Inspection, and Process Control for Microlithography XXI (PART 3 ed.). [65183P] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 6518, No. PART 3). https://doi.org/10.1117/12.712307

Plasma-Assisted Cleaning by Electrostatics (PACE). / Lytle, W. M.; Shin, H.; Ruzic, D. N.

Metrology, Inspection, and Process Control for Microlithography XXI. PART 3. ed. 2007. 65183P (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 6518, No. PART 3).

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

Lytle, WM, Shin, H & Ruzic, DN 2007, Plasma-Assisted Cleaning by Electrostatics (PACE). in Metrology, Inspection, and Process Control for Microlithography XXI. PART 3 edn, 65183P, Proceedings of SPIE - The International Society for Optical Engineering, no. PART 3, vol. 6518, Metrology, Inspection, and Process Control for Microlithography XXI, San Jose, CA, United States, 2/26/07. https://doi.org/10.1117/12.712307
Lytle WM, Shin H, Ruzic DN. Plasma-Assisted Cleaning by Electrostatics (PACE). In Metrology, Inspection, and Process Control for Microlithography XXI. PART 3 ed. 2007. 65183P. (Proceedings of SPIE - The International Society for Optical Engineering; PART 3). https://doi.org/10.1117/12.712307
Lytle, W. M. ; Shin, H. ; Ruzic, D. N. / Plasma-Assisted Cleaning by Electrostatics (PACE). Metrology, Inspection, and Process Control for Microlithography XXI. PART 3. ed. 2007. (Proceedings of SPIE - The International Society for Optical Engineering; PART 3).
@inproceedings{71dff5cee5c4481c9d1443abc2e14302,
title = "Plasma-Assisted Cleaning by Electrostatics (PACE)",
abstract = "The need for a non-contact contamination removal technique has been exhibited by various companies. While an EUV compatible pellicle is being researched, contamination will become an ongoing problem to overcome. Some techniques that are being considered for contamination removal include the use of Shockwaves which are potentially damaging, as well as rolling contamination off of a surface. Depending on feature size, rolling or moving of contamination horizontally across a surface is limited as there is a strong possibility that the contamination will get trapped in between features. Plasma- Assisted Cleaning by Electrostatics (PACE) is a non-contact removal method that utilizes charge imbalances to remove particles perpendicular to the surface. A positive bias is applied to the top of the sample for conducting samples or to the substrate behind an insulating sample. This positive bias draws in net electrons from the plasma to the entire surface. The contamination charges negatively and the positive bias is removed and switched with a negative bias. The combination of substrate/particle charge imbalance as well as electric field effects from the plasma sheath provide for the removal mechanism. Surface damage has been avoided by staying below the sputtering threshold for the surface materials of the samples. Recent tests on 2.5 nm ruthenium on Si/Quartz using the PACE technique coupled with Atomic Force Microscopy data has shown no roughening of the surface and approximately 90{\%} removal efficiency of contamination. In addition, Auger Electron Spectroscopy scans show no removal of the 2.5 nm ruthenium capping layer. Removal results for 30 nm to 220 nm PSL particles as well as select other contamination materials on samples comparable with EUV masks in addition to damage assessments will be presented.",
author = "Lytle, {W. M.} and H. Shin and Ruzic, {D. N.}",
year = "2007",
month = "10",
day = "15",
doi = "10.1117/12.712307",
language = "English (US)",
isbn = "0819466379",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
number = "PART 3",
booktitle = "Metrology, Inspection, and Process Control for Microlithography XXI",
edition = "PART 3",

}

TY - GEN

T1 - Plasma-Assisted Cleaning by Electrostatics (PACE)

AU - Lytle, W. M.

AU - Shin, H.

AU - Ruzic, D. N.

PY - 2007/10/15

Y1 - 2007/10/15

N2 - The need for a non-contact contamination removal technique has been exhibited by various companies. While an EUV compatible pellicle is being researched, contamination will become an ongoing problem to overcome. Some techniques that are being considered for contamination removal include the use of Shockwaves which are potentially damaging, as well as rolling contamination off of a surface. Depending on feature size, rolling or moving of contamination horizontally across a surface is limited as there is a strong possibility that the contamination will get trapped in between features. Plasma- Assisted Cleaning by Electrostatics (PACE) is a non-contact removal method that utilizes charge imbalances to remove particles perpendicular to the surface. A positive bias is applied to the top of the sample for conducting samples or to the substrate behind an insulating sample. This positive bias draws in net electrons from the plasma to the entire surface. The contamination charges negatively and the positive bias is removed and switched with a negative bias. The combination of substrate/particle charge imbalance as well as electric field effects from the plasma sheath provide for the removal mechanism. Surface damage has been avoided by staying below the sputtering threshold for the surface materials of the samples. Recent tests on 2.5 nm ruthenium on Si/Quartz using the PACE technique coupled with Atomic Force Microscopy data has shown no roughening of the surface and approximately 90% removal efficiency of contamination. In addition, Auger Electron Spectroscopy scans show no removal of the 2.5 nm ruthenium capping layer. Removal results for 30 nm to 220 nm PSL particles as well as select other contamination materials on samples comparable with EUV masks in addition to damage assessments will be presented.

AB - The need for a non-contact contamination removal technique has been exhibited by various companies. While an EUV compatible pellicle is being researched, contamination will become an ongoing problem to overcome. Some techniques that are being considered for contamination removal include the use of Shockwaves which are potentially damaging, as well as rolling contamination off of a surface. Depending on feature size, rolling or moving of contamination horizontally across a surface is limited as there is a strong possibility that the contamination will get trapped in between features. Plasma- Assisted Cleaning by Electrostatics (PACE) is a non-contact removal method that utilizes charge imbalances to remove particles perpendicular to the surface. A positive bias is applied to the top of the sample for conducting samples or to the substrate behind an insulating sample. This positive bias draws in net electrons from the plasma to the entire surface. The contamination charges negatively and the positive bias is removed and switched with a negative bias. The combination of substrate/particle charge imbalance as well as electric field effects from the plasma sheath provide for the removal mechanism. Surface damage has been avoided by staying below the sputtering threshold for the surface materials of the samples. Recent tests on 2.5 nm ruthenium on Si/Quartz using the PACE technique coupled with Atomic Force Microscopy data has shown no roughening of the surface and approximately 90% removal efficiency of contamination. In addition, Auger Electron Spectroscopy scans show no removal of the 2.5 nm ruthenium capping layer. Removal results for 30 nm to 220 nm PSL particles as well as select other contamination materials on samples comparable with EUV masks in addition to damage assessments will be presented.

UR - http://www.scopus.com/inward/record.url?scp=35148818406&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=35148818406&partnerID=8YFLogxK

U2 - 10.1117/12.712307

DO - 10.1117/12.712307

M3 - Conference contribution

AN - SCOPUS:35148818406

SN - 0819466379

SN - 9780819466372

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - Metrology, Inspection, and Process Control for Microlithography XXI

ER -