Development of an ultrasonic system for super-precise measurement of zero-CTE temperature of EUVL-grade TiO2-SiO2 ultra-low-expansion glasses

Jun Ichi Kushibiki, Mototaka Arakawa, Yuji Ohashi, Toshio Sannomiya, Yuko Maruyama

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

2 Citations (Scopus)


This paper presents the development of a practical system for super-precise evaluation of zero-CTE temperatures T(zero- CTE) of TiO2-SiO 2 glasses for extreme ultraviolet lithography (EUVL) by measuring leaky surface-acoustic-wave (LSAW) velocity VLSAW with a line-focus-beam ultrasonic material characterization (LFB-UMC) system. This new system can evaluate T(zero-CTE) from 20 to 150°C on the surfaces of glass substrates for photomasks and optical mirrors located at different positions in EUVL systems. This system operates in a stabilized temperature measurement environment (e.g., 23.00°C). It was demonstrated at 225 MHz for homogenized TiO2-SiO2 glass specimens with different annealing temperatures and realized an extremely homogeneous glass ingot with a ΔT(zero-CTE) of 1.6°C around 23.2°C. This ultrasonic system enables both glass manufacturers and users to speedily inspect all glass substrates with reliable data of T(zero-CTE).

Original languageEnglish
Title of host publicationExtreme Ultraviolet (EUV) Lithography
Publication statusPublished - 2010 Jun 17
EventExtreme Ultraviolet (EUV) Lithography - San Jose, CA, United States
Duration: 2010 Feb 222010 Feb 25

Publication series

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


OtherExtreme Ultraviolet (EUV) Lithography
CountryUnited States
CitySan Jose, CA


  • TiO-SiO ultra-low-expansion glass
  • coefficient of thermal expansion
  • leaky surface acoustic waves
  • line-focus-beam ultrasonic material characterization system
  • velocity measurement

ASJC Scopus subject areas

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

Fingerprint Dive into the research topics of 'Development of an ultrasonic system for super-precise measurement of zero-CTE temperature of EUVL-grade TiO<sub>2</sub>-SiO<sub>2</sub> ultra-low-expansion glasses'. Together they form a unique fingerprint.

Cite this