A Study on the Etching Characteristics of $YMnO_3$ Thin Films in High Density $Cl_2$/Ar Plasma

고밀도 $Cl_2$/Ar 플라즈마를 이용한 $YMnO_3$ 박막의 식각 특성에 관한 연구

  • 민병준 (중앙대학교 전자전기공학부) ;
  • 김창일 (중앙대학교 전자전기공학부) ;
  • 장의구 (중앙대학교 전자전기공학부)
  • Published : 2000.11.01

Abstract

Ferroelectric YMnO$_3$ thin films are excellent dielectric materials for high integrated ferroelectric random access memory (FRAM) with metal-ferroelectric-silicon field effect transistor (MFSFET) structure. In this study, YMnO$_3$ thin films were etched with C1$_2$/Ar gas chemistries in inductively coupled plasma (ICP). The maximum etch rate of YMnO$_3$ thin films is 285 $\AA$/min under C1$_2$/Ar of 10/0, 600 W/-200 V and 15 mTorr. The selectivities of YMnO$_3$ over CeO$_2$ and $Y_2$O$_3$ are 2.85, 1.72, respectively. The results of x-ray photoelectron spectroscopy (XPS) reflect that Y is removed dominantly by chemical reaction between Y and Cl, while Mn is removed more effective by Ar ion bombardment than chemical reaction. The results of secondary ion mass spectrometer (SIMS) were equal to these of XPS. The etch profile of the etched YMnO$_3$ film is approximately 65$^{\circ}$and free of residues at the sidewall.

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