Thermal atomic layer etching of cobalt using plasma chlorination and chelation with hexafluoroacetylacetone
- 주제(키워드) Atomic layer etching (ALE) , Cobalt etching , Density functional theory (DFT)
- 주제(기타) Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter
- 설명문(일반) [Kim, Yongjae; Lee, Hyeongwu] Sungkyunkwan Univ SKKU, Dept Nano Sci & Technol, Suwon 16419, South Korea; [Kim, Yongjae; Lee, Hyeongwu; Chae, Heeyeop] Sungkyunkwan Univ SKKU, SKKU Adv Inst Nanotechnol St, Suwon 16419, South Korea; [Chae, Somin; Lee, Sangheon] Ewha Womans Univ, Dept Chem Engn & Mat Sci, Seoul 03760, South Korea; [Chae, Somin; Lee, Sangheon] Ewha Womans Univ, Grad Program Syst Hlth Sci & Engn, Seoul 03760, South Korea; [Ha, Heeju; Chae, Heeyeop] Sungkyunkwan Univ SKKU, Sch Chem Engn, Suwon 16419, South Korea
- 관리정보기술 faculty
- 등재 SCIE, SCOPUS
- 발행기관 ELSEVIER
- 발행년도 2023
- URI http://www.dcollection.net/handler/ewha/000000204304
- 본문언어 영어
- Published As https://doi.org/10.1016/j.apsusc.2023.156751
초록/요약
In this study, a thermal atomic layer etching process for Co comprising two steps--plasma chlorination and chelation with hexafluoroacetylacetone (Hhfac)--was developed. The Co surface was chlorinated with BCl3 plasma to form CoCl2 in the plasma chlorination step, and the thickness of CoCl2 was measured using secondary ion mass spectrometry. In the chelation step, CoCl2 was removed from the surface by forming a volatile etch product at temperatures >= 150 degrees C, and the Etch per cycle (EPC) of Co was constant in the temperature range of 150-175 degrees C. Above 200 degrees C, the EPC of Co decreased owing to Hhfac decomposition at high process temperatures. The EPC of Co increased from 1.1 to 2.1 nm as the chlorination time increased from 30 to 90 s; however, it saturated with increasing Hhfac exposure time. Density functional theory calculations showed that the adsorp-tion of Hhfac on the chlorinated Co surface is the rate-determining-step in the chelation process of chlorinated cobalt surfaces. The final reaction product of the chelation reaction is suggested to be CoCl2(hfac). The Hhfac adsorption step is the rate-determining-step in the chelation process of chlorinated cobalt surfaces.
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