Regular Articles

Real-time critical dimension measurement of thin film transistor liquid crystal display patterns using optical coherence tomography

[+] Author Affiliations
Sung-Hoon Park

Seoul National University, School of Mechanical and Aerospace Engineering, Seoul 151-742, Republic of Korea

Tai-Wook Kim

SNU Precision Co., Ltd., #201, 1629-2, Nakseongdae-dong, Kwanak-gu, Seoul 151-818, Republic of Korea

Jeong-Ho Lee

Applied Optical Equipment Group, Samsung Electro-Mechanics, 314, Maetan 3-dong, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-743, Republic of Korea

Heui-Jae Pahk

Seoul National University, School of Mechanical and Aerospace Engineering, Seoul 151-742, Republic of Korea

J. Electron. Imaging. 23(1), 013001 (Jan 02, 2014). doi:10.1117/1.JEI.23.1.013001
History: Received June 14, 2013; Revised October 7, 2013; Accepted December 2, 2013
Text Size: A A A

Abstract.  A coherence scanning tomographic imaging system with an innovative signal correction method is presented for a critical dimension (CD) measurement of thin film transistor liquid crystal display patterns having multiple focus positions within a single field of view. To facilitate the analyzing of coherence signals, a simulation model based on fast Fourier transform method is proposed, and its simulated result is compared with the coherence signals from the actual experiments. The comparison shows that the majority of frequency characteristics from simulation modeling results are matched with the experimental results. However, in many edge regions, discrepancies in frequency characteristics between the two results are observed. For the interpretation of signals, those are different from the simulation modelling, in that the intensity of its pixels has been corrected by an innovatively proposed connected neighborhoods window method with multiple window sizes. By using this combination of tomographic imaging and edge correction methods, the repeatability of the CD measurement of multiple focus position samples is significantly enhanced compared to the results with a plain two-dimensional optics. The proposed method is also compared with the autofocus methods including gradient magnitude method and frequency domain method and other tomographic imaging methods, including the phase shift method and the Hilbert transform method to show the advantages in the processing time.

© 2014 SPIE and IS&T

Citation

Sung-Hoon Park ; Tai-Wook Kim ; Jeong-Ho Lee and Heui-Jae Pahk
"Real-time critical dimension measurement of thin film transistor liquid crystal display patterns using optical coherence tomography", J. Electron. Imaging. 23(1), 013001 (Jan 02, 2014). ; http://dx.doi.org/10.1117/1.JEI.23.1.013001


Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement
  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.