Damages of Etched (Ba, Sr) $TiO_3$Thin Films by Inductively Coupled Plasmas

유도결합 플라즈마에 의한 (Ba,Sr)$TiO_3$박막의 식각 손상에 관한 연구

  • 최성기 (중앙대학교 전기전자공학부) ;
  • 김창일 (중앙대학교 전기전자공학부) ;
  • 장의구 (중앙대학교 전기전자공학부)
  • Published : 2001.10.01


High dielectric (Ba, Sr) TiO$_3$ thin films were etched in an inductively coupled plasma (ICP) as a function of Cl$_2$/Ar mixing ration. Under Cl$_2$(20)/Ar(80), the maximum etch rate of the BST films was 400 $\AA$/mim and selectivities of BST to Pt and PR were obtained 0.4 and 0.2, respectively. Etching products were redeposited on the surface of BST and resulted in varying the nature of crystallinity. Therefore, we investigated the etched surface of BST by x-ray photoelectron spectroscopy (XPS) atomic force microscopy (AFM) and x-ray diffraction (XRD). From the result of XPS analysis, we found that residues of Ba-Cl and Ti-Cl bonds remained on the surface of the etched BST for high boiling point. The morphology of the etched surfact was analyzed by AFM. A smoothsurface(roughness ~2.8nm) ws observed under Cl$_2$(20)/Ar(80), rf power of 600 W, dc bias voltage of -250 V and pressure of 10 mTorr. This changed the nature of the crystallinity of BST. From the result of XRD analysis, the crystallinities of the etched BST film under Ar only and Cl$_2$(20)/Ar(80) were maintained as similar to as-deposited BST. However, intensity of BST(100) orientation under Cl$_2$ only plasma was abruptly decreased. This indicated that CI compounds were redeposited on the etched BST surface and resulted in changed of the crystallinity of BST during the etch process.


  1. 전기전자재료학회지 v.9 no.4 ULSI DRAM의 capacitor 절연막용 BST(Barium Strontium Titanate)박막의 제작과 특성에 관한 연구 류정선;강성준;윤영섭
  2. 전기전자재료 v.13 no.4 강유전체 및 전극 재료의 식각 기술 동향 김창일;김동표;민병준
  3. J. Vac. Sci. Tech. v.A17 Study on surface reaction of (Ba,Sr)TiO₃thin films by high density plasma etching Seung-Bum Kim;Chang-Il Kim;Eui-Goo Chang;Guen-Young Yeom
  4. 전기전자재료학회논문지 v.11 no.10 ICP에 의한 BCl₃/Cl₂플라즈마내에서 Pt 박막의 식각 특성 김창일;권광호
  5. J. Vac. Sci. Tech. v.A18 Etch mechanism of (Ba,Sr)TiO₃films in high density Cl₂/BCl₃/Ar plasma Seun-Bum Kim;Yong-Hyuk Lee;Tae-Hyung Kim;Geun-Young Yeom;Chang-Il Kim
  6. Jpn. J. Appl. Phys. v.39 no.4B Etching Characteristics and Mechanism of $Ba_{0.5}Sr_{0.3}TiO_3$Thin Films in an Inductively coupled Plasma D. S. Wuu;F. C. Liao;N. H. Kuo;R. H. Horng;M. K. Lee
  7. IBM J. Res. Develop. v.43 Plasma processing damage in etching and deposition S. J. Fonash
  8. J. Appl. Phys. v.58 Silicon damage caused by CCl₄reactive ion etching: Its characterization and removal by rapid thermal annealing S. J. Fonash;R. Singh;A. Rohatgi;P. Rai-Choudhury;P. J. Caplan;E. H. Poindexter
  9. J. Appl. Phys. v.63 Damage to shallow $n^{+}/p and p^{+}/n$ junctions by CHF₃+CO₂reactive ion etching I. W. Wu;R. A. Street;J. C. Mikkenslen, Jr.
  10. J. Appl. Phys. v.54 Damage induced in Si by ion milling or reactive ion etching S. W. Pang;D. D. Rathman;D. J. Silversmith;R.W. Mountain;P. D. DeGraff
  11. Hand Book of X-ray Photoelectron Spectroscopy J. Chastain(ed.)