Journal of the Semiconductor & Display Technology (반도체디스플레이기술학회지)

The Korean Society Of Semiconductor & Display Technology (한국반도체디스플레이기술학회)
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Improved Margin of Absorber Pattern Sidewall Angle Using Phase Shifting Extreme Ultraviolet Mask

위상변위 극자외선 마스크의 흡수체 패턴의 기울기에 대한 오차허용도 향상

  • Jang, Yong Ju (Department of Nanoscale Semiconductor Engineering) ;
  • Kim, Jung Sik (Department of Nanoscale Semiconductor Engineering) ;
  • Hong, Seongchul (Department of Materials Science and Engineering, Hanyang University) ;
  • Ahn, Jinho (Department of Materials Science and Engineering, Hanyang University)
  • 장용주 (한양대학교 공과대학 나노반도체공학과) ;
  • 김정식 (한양대학교 공과대학 나노반도체공학과) ;
  • 홍성철 (한양대학교 공과대학 신소재공학과) ;
  • 안진호 (한양대학교 공과대학 신소재공학과)
  • Received : 2016.05.23
  • Accepted : 2016.06.10
  • Published : 2016.06.30
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Abstract

Sidewall angle (SWA) of an absorber stack in extreme ultraviolet lithography mask is considered to be $90^{\circ}$ ideally, however, it is difficult to obtain $90^{\circ}$ SWA because absorber profile is changed by complicated etching process. As the imaging performance of the mask can be varied with this SWA of the absorber stack, more complicated optical proximity correction is required to compensate for the variation of imaging performance. In this study, phase shift mask (PSM) is suggested to reduce the variation of imaging performance due to SWA change by modifying mask material and structure. Variations of imaging performance and lithography process margin depending on SWA were evaluated through aerial image and developed resist simulations to confirm the advantages of PSM over the binary intensity mask (BIM). The results show that the variations of normalized image log slope and critical dimension bias depending on SWA are reduced with PSM compared to BIM. Process margin for exposure dose and focus was also improved with PSM.

Keywords

References

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