Journal of the Semiconductor & Display Technology (반도체디스플레이기술학회지)

The Korean Society Of Semiconductor & Display Technology (한국반도체디스플레이기술학회)
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Analysis of Si Etch Uniformity of Very High Frequency Driven - Capacitively Coupled Ar/SF6 Plasmas

VHF-CCP 설비에서 Ar/SF6 플라즈마 분포가 Si 식각 균일도에 미치는 영향 분석

  • Lim, Seongjae (Department of Energy Systems Engineering, Seoul National University) ;
  • Lee, Ingyu (Department of Energy Systems Engineering, Seoul National University) ;
  • Lee, Haneul (Department of Energy Systems Engineering, Seoul National University) ;
  • Son, Sung Hyun (Department of Energy Systems Engineering, Seoul National University) ;
  • Kim, Gon-Ho (Department of Energy Systems Engineering, Seoul National University)
  • 임성재 (서울대학교 에너지시스템공학부) ;
  • 이인규 (서울대학교 에너지시스템공학부) ;
  • 이하늘 (서울대학교 에너지시스템공학부) ;
  • 손성현 (서울대학교 에너지시스템공학부) ;
  • 김곤호 (서울대학교 에너지시스템공학부)
  • Received : 2021.11.08
  • Accepted : 2021.11.25
  • Published : 2021.12.31
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Abstract

The radial distribution of etch rate was analyzed using the ion energy flux model in VHF-CCP. In order to exclude the effects of polymer passivation and F radical depletion on the etching. The experiment was performed in Ar/SF6 plasma with an SF6 molar ratio of 80% of operating pressure 10 and 20 mTorr. The radial distribution of Ar/SF6 plasma was diagnosed with RF compensated Langmuir Probe(cLP) and Retarding Field Energy Analyzer(RFEA). The radial distribution of ion energy flux was calculated with Bohm current times the sheath voltage which is determined by the potential difference between the plasma space potential (measured by cLP) and the surface floating potential (by RFEA). To analyze the etch rate uniformity, Si coupon samples were etched under the same condition. The ion energy flux and the etch rate show a close correlation of more than 0.94 of R2 value. It means that the etch rate distribution is explained by the ion energy flux.

Keywords

Acknowledgement

이 논문은 2020년 정부(과학기술정보통신부)의 재원으로 국가과학기술연구회 2020년도 미래선도형 융합연구단사업 (No. CRC-20-01-NFRI) 및 BK21플러스 사업(No. 4199990314119) 및 산업통상자원부(20006534)와 KSRC 지원사업인 미래반도체소자 원천기술개발사업에서 지원을 받아 수행된 연구임.

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