A study on etching mechanism of SBT thin flim by using Ar/$CHF_3$plasma

Ar/$CHF_34$플라즈마를 이용한 SBT 박막에 대한 식각 메카니즘 연구

  • 서정우 (중앙대학교 전자전기공학부) ;
  • 장의구 (중앙대학교 전자전기공학부) ;
  • 김창일 (중앙대학교 전자전기공학부) ;
  • 이원재 (한국전자통신연구원 회로소자기술연구소) ;
  • 유병곤 (한국전자통신연구원 회로소자기술연구소)
  • Published : 2000.03.01

Abstract

In this study the SrBi$_2$Ta$_2$$O_{9}$ (SBT) thin films were etched by using magnetically enhanced inductively coupled Ar/CHF$_3$plasma as function of CHF$_3$/(Ar+CHF$_3$)gas mixing ratio. Maximum etch rate of SBT thin films was 1650 $\AA$/min and the selectivities of SBT to Pt and photoresist(PR) were 1.35 and 0.94 respectively under CHF$_3$/(Ar+CHF$_3$) of 0.1 For study on etching mechanism of SBT thin film X-ray photoelectron spectroscopy (XPS) surface analyses and secondary ion mass spectrometry (SIMS) mass analysis of etched SBT surfaces were performed. Among the elements of SBT thin film. M(Sr, Bi, Ta)-O bonds are broken by Ar ion bombardment and form SrF and TaF$_2$by chemical reaction with F. SrF and TaF$_2$are removed more easily by Ar ion bombardment. Scanning electron microscopy(SEM) was used for the profile examination of etched SBT film and the cross-sectional SEM profile of etched SBT film under CHF$_3$(Ar+CHF$_3$) of 0.1 was about 85$^{\circ}$X>.

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