Patent · US Expired

Low thermal distortion extreme-UV lithography reticle

US6441885B2 · kind B2 · utility

1Cited by
0References
25Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 10, 2001
Grant dateAug 27, 2002
Priority date—
Expiry dateJul 10, 2021

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03F7/2004
  • WIPO fieldMicro-structural and nano-technology
  • WIPO sectorChemistry

Abstract

Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.