Abstract
Abstract
Magnetic tunneling junction (MTJ) materials such as CoFeB, Co, Pt, MgO, and the hard mask material such as W and TiN were etched with a reactive ion beam etching (RIBE) system using H2/NH3. By using gas mixtures of H2 and NH3, especially with the H2/NH3( 2:1) ratio, higher etch rates of MTJ related materials and higher etch selectivities over mask materials (>30) could be observed compared to those etching using pure H2( no etching) and NH3. In addition, no significant chemical and physical damages were observed on etched magnetic materials surfaces and, for CoPt and MTJ nanoscale patterns etched by the H2/NH3( 2:1) ion beam, highly anisotropic etch profiles >83° with no sidewall redeposition could be observed. The higher etch rates of magnetic materials such as CoFeB by the H2/NH3( 2:1) ion beam compared to those by H2 ion beam or NH3 ion beam are believed to be related to the formation of volatile metal hydrides (MH, M = Co, Fe, etc) through the reduction of M-NHx( x = 1 ∼ 3) formed in the CoFeB surface by the exposure to NH3 ion beam. It is believed that the H2/NH3 RIBE is a suitable technique in the etching of MTJ materials for the next generation nanoscale spin transfer torque magnetic random access memory (STT-MRAM) devices.
Subject
Electrical and Electronic Engineering,Mechanical Engineering,Mechanics of Materials,General Materials Science,General Chemistry,Bioengineering
Reference20 articles.
1. Review modern magnetic materials in data storage;Comstock;J. Mater. Sci., Mater. Electron.,2002
2. Lower-current and fast switching of a perpendicular TMR for high speed and high density spin-transfer-torque MRAM;Kishi,2008
3. A new spin on magnetic memories;Kent;Nat. Nanotechnol.,2015
4. A perpendicular-anisotropy CoFeB–MgO magnetic tunnel junction;Ikeda;Nat. Mater.,2010
5. Etching of CoFeB Using CO/NH3 in an inductively coupled plasma etching system;Park;J. Electrochem. Soc.,2011
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献