TY - GEN
T1 - Improvement of photomask CD uniformity using spatially resolved optical emission spectroscopy
AU - Junhwa-Jung,
AU - Kim, Youngkeun
AU - Jang, Il Yong
AU - Kim, Byung Gook
AU - Jeon, Chan Uk
AU - Kang, Minwook
AU - Lee, Changmin
AU - Hahn, Jae W.
N1 - Publisher Copyright:
© 2016 SPIE.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016
Y1 - 2016
N2 - 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.
AB - 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.
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U2 - 10.1117/12.2242406
DO - 10.1117/12.2242406
M3 - Conference contribution
AN - SCOPUS:85006992975
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Photomask Technology 2016
A2 - Kasprowicz, Bryan S.
A2 - Buck, Peter D.
PB - SPIE
T2 - Photomask Technology 2016
Y2 - 12 September 2016 through 14 September 2016
ER -