Improvement of photomask CD uniformity using spatially resolved optical emission spectroscopy

Junhwa-Jung, Youngkeun Kim, Il Yong Jang, Byung Gook Kim, Chan Uk Jeon, Minwook Kang, Changmin Lee, Jae W. Hahn

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

1 Citation (Scopus)


According to the design rule shrinkage, more precise control of mask CD, including mean to target and uniformity, is required in lithography process. Since dry etching is one of the most critical processes to determine CD qualities in photomask, optical emission spectroscopy (OES) to monitor plasma status during dry etching process could be useful. However, it is not possible to obtain distributional information of plasma with a conventional OES tool because the OES acquires totally integrated signals of light from the chamber. To overcome the limit of OES, we set up a spatially resolved (SR)-OES tool and measure the distribution of radicals in plasma during dry etch process. The SR-OES consists of a series of lenses, apertures, and a pinhole as a spatial filter which enable us to focus on certain area in the chamber, to extract the emitted light from plasma, and to perform the spectroscopic analysis. The Argon based actinometry combined with SR-OES shows spatially distinguished peaks related to the etch rate of Chromium on photomask. In this paper, we present experimental results of SR-OES installed on a commercial photomask dry etcher and discuss its practical effectiveness by correlation of the results with chamber etch rate.

Original languageEnglish
Title of host publicationPhotomask Technology 2016
EditorsBryan S. Kasprowicz, Peter D. Buck
ISBN (Electronic)9781510603745
Publication statusPublished - 2016
EventPhotomask Technology 2016 - San Jose, United States
Duration: 2016 Sep 122016 Sep 14

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherPhotomask Technology 2016
Country/TerritoryUnited States
CitySan Jose

Bibliographical note

Publisher Copyright:
© 2016 SPIE.

All Science Journal Classification (ASJC) codes

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


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