Modified Illumination with a Concentric Circular Grating at the Backside of a Photomask

마스크 뒷면에 동심원 격자를 사용한 변형조명 방법

  • 오용호 (원광대학교 전기전자 및 정보공학부) ;
  • 고춘수 (원광대학교 자연과학부) ;
  • 임성우 (원광대학교 자연과학부) ;
  • 이재철 (원광대학교 전기전자 및 정보공학부)
  • Published : 2005.03.01


Modified illumination techniques have been used to enhance the resolution of the sub-wavelength lithography. But, since they shield the central part of incident light, the light efficiency is seriously degraded, which in turn reduces the throughput of a lithography process. In this research, we introduced an annular illumination structure that enhances the light efficiency with a concentric circular grating at the backside of a photomask. The efficiency of the structure was theoretically analyzed.


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