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Language: korean

Conflict of Interest: In relation to this article, we declare that there is no conflict of interest.

Publication history: Received March 16, 2005
Accepted June 14, 2005

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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고밀도 플라즈마 식각에 의한 CoTb과 CoZrNb 박막의 식각 특성

Etch Characteristics of CoTb and CoZrNb Thin Films by High Density Plasma Etching

신별 박익현 정지원^†

Byul Shin Ik Hyun Park Chee Won Chung^†

인하대학교 화학공학과, 402-751 인천시 남구 용현동 253

Department of Chemical Engineering, Inha University, 253, Yonghyun-dong, Nam-gu, Incheon 402-751, Korea

cwchung@inha.ac.kr

Korean Chemical Engineering Research, August 2005, 43(4), 531-536(6), NONE Epub 27 September 2005

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Abstract

포토리지스트 마스크로 패턴된 CoTb 및 CoZrNb 자성 박막에 대한 유도 결합 플라즈마 반응성 이온 식각이 Cl2/Ar와 C2F6/Ar 가스를 이용하여 진행되었고 식각 속도와 식각 프로파일 측면에서 조사되었다. Cl2와 C2F6 가스의 농도가 증가함에 따라서 자성 박막들의 식각 속도는 감소하였고 식각 경사는 낮아졌다. 자성 박막들의 식각 가스로서 Cl2/Ar이 빠른 식각 속도와 가파른 식각 경사를 얻는데 있어서 C2F6/Ar 보다 더 효과적이었다. Coil rf power의 증가는 플라즈마 내의 Ar 이온과 라디칼의 밀도를 증가시키고 dc bias voltage의 증가는 기판으로 스퍼터되는 Ar 이온의 에너지를 증가시키기 때문에 coil rf power와 dc bias voltage가 증가할수록 식각 속도와 식각 경사는 증가하였지만 패턴의 측면에서 재증착이 일어났다. 자성 박막들의 적층으로 형성된 magnetic tunnel junction stack에 고밀도 플라즈마 반응성 이온 식각을 적용하여, 높은 식각 경사와 재증착이 없는 깨끗한 식각 프로파일을 얻었다.

Inductively coupled plasma reactive ion etching of Co Tb and CoZrNb magnetic materials with the photoresist mask was performed using Cl2/Ar and C2F6/Ar gas mixtures and characterized in terms of etch rate and etch profile. As the concentrations of Cl2 and C2F6 gases increased, the etch rates of magnetic films decreased and the etch slopes became slanted. The Cl2/Ar gas was more effective in obtaining fast etch rate and steep sidewall slope than the C2F6/Ar gas. As the coil rf power and dc bias increased, fast etch rate and steep etch slope were obtained but the redeposition on the sidewall was observed. This is due to the increase of ion and radical densities in plasma with increasing high density reactive ion etching to magnetic tunnel junction stack containing various magnetic films and metal oxide, steep etch slope and clean etch profile without redeposition were obtained.

Keywords

CoTb CoZrNb Reactive Ion Etching Magnetic Tunnel Junction Inductively Coupled Plasma

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