The Study on the Surface Reaction of $SrBi_{2}Ta_{2}O_{9}$ Film by Magnetically Enhanced Inductively Coupled Plasma

MEICP 식각에 의한 SBT 박막의 표면 반응 연구

  • Kim, Dong-Pyo (Dept.of Electronics Electric Engineering, Chungang University) ;
  • Kim, Chang-Il (Dept.of Electronics Electric Engineering, Chungang University)
  • 김동표 (중앙대학교 전자전기공학부) ;
  • 김창일 (중앙대학교 전자전기공학부)
  • Published : 2000.04.01

Abstract

Recently, SrBi$_{2}$Ta$_{2}$ $O_{9}$(SBT) and Pb(Zr,Ti) $O_{3}$(PZT) were much attracted as materials of capacitor for ferroelectric random access memory(FRAM) with higher read/ write speed, lower power consumption and nonvolartility. SBT thin film has appeared as the most prominent fatigue free and low operation voltage. To highly integrate FRAM, SBT thin film has to be etched. A lot of papers have been reported over growth of SBT thin film and its characteristics. However, there are few reports about etching SBT thin film owing to difficult of etching ferroelectric materials. SBT thin film was etched in CF$_{4}$Ar plasma using magnetically enhanced inductively coupled plasma (MEICP) system. In order to investigate the chemical reaction on the etched surface of SBT thin films, X-ray Photoelecton spectrosocpy (XPS) and Secondary ion mass spectroscopy(SIMS) was performed.

최근에 빠른 쓰기/읽기 속도, 적은 소비 전력과 비휘발성을 가지는 메모리 캐패시터의 유전 재료로서 SrBi/sub 2/Ta/sub 2/O/sub 9/(SBT)에 대한 관심이 집중되고 있다. 강유전체 물질을 이용한 고밀도 FeRAM을 생산하기 위하여서는 식각에 의한 패턴이 형성되어야 한다. 강유전체 물질의 성장과 그 전기적 특성에 관한 연구와 발표는 많이 발표 되고 있다. 그러나, 강유전체 물질의 식각의 어려움 때문에 SBT 박막 식각에 관한 연구는 거의 전무하다고 할 수 있다. 그러므로, SBT 박막의 식각의 특성을 알아보기 위하여, SBT 박막은 CF/sub 4/Ar 가스 플라즈마를 이용하여 MEICP로 식각 되어졌다. XPS를 이용하여 식각 된 SBT 박막의 표면에서의 화학 반응을 분석하였고, XPS 분석을 검증하기 위하여 SIMS 분석을 하여 비교하였다.

Keywords

References

  1. O. Auiciello and A. I. Kingon, 'Electrical characterization of $Pt/SrBi_2Ta_2O_9/Pt$ capacitors fabricated by the pulsed laser ablated deposition technique', J. Vac. Sci. Technol. A, 14(3) May/June, pp.900-904, 1996 https://doi.org/10.1116/1.580411
  2. Seshu B. Desu and Wei Pan,' Reactive etching of ferroelectric $SrBi_2TaxNb_2-xO_9$ thin films', Appl. Phys. Lett. 68(4), pp. 566-568, 1996 https://doi.org/10.1063/1.116402
  3. Chee-Won Chung and Chang-Jung Kim, 'Etching Effects on Ferroelectric Capacitors with Multilayered Electrodes', Jpn. J. Appl. Phys, Vol. 36, pp.2747-2753, 1997 https://doi.org/10.1143/JJAP.36.2747
  4. Won-Jae Lee, Chang-Ho Shin, Chae-Ryong Cho, Jong-Sun Ryu, Bo-Woo Kim, Byung-Gon Yu and Kyoung-Ik Cho, 'Electrical Properties of $SrBi_2Ta_2O_9/Insulator/Si$ Structures with Various Insulators', Jpn. J. Appl. Phys, Vol. 38, pp.2039-2043, 1999 https://doi.org/10.1143/JJAP.38.2039
  5. Glowing Discharge Process, edited by Brian Chapman(Wiley inter science, New York, 1980)
  6. Handbook of Sputtering, edited by K. Wasa and S. Hayakawa(Noyes Park Ridge,NJ, 1992)
  7. Seung-Bum Kim, Chang-Il Kim, Eui-Goo Chang, Geun-Young Yeom, 'Study on Surface Reaction $(Ba,Sr)TiO_3$ Thin Films by High Density Plasma Etching', J. Vac. Sci. Technol. A. Jul/Aug. 1999