Effect of reactive gas (oxygen/chlorine/fluorine) etching on the magnetic flux of a high moment write pole material

Journal Article · Sat May 15 00:00:00 EDT 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3356231· OSTI ID:21476202

Jinqiu, Zhang; Feng, Liu; Lifan, Chen; Miloslavsky, Lena ^[1]

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1. Western Digital Corporation, 1250 Reliance Way, Fremont, California 94539 (United States)

Effect of reactive gas (oxygen/chlorine/fluorine) etching on NiFe magnetic properties was investigated. Experimental data showed 40% magnetic property degradation for F-containing gas etching, 10% degradation for O-containing gas etching, and 5% degradation for Cl-containing gas etching processes. X-ray diffraction analysis indicated that the crystallographic orientation remained the same upon the reactive gas etching, which is due to the low ion energy in plasma etching process as opposed to ion milling process with high input energy. It is proposed that the reported magnetic property degradation was mainly caused by the nonmagnetic dead layer formation, rather than the changes in the crystallographic orientation. The dead layer was determined by the NiFe thickness dependence of remnant magnetic flux variations between pre-etched and postetched samples. The dead layer remained nearly constant for O-containing gas etching process with increasing plasma processing time. The nonmagnetic dead layer of {approx}40-50 A formed in O-containing etching gas was observed in transmission electron microscopy cross-sectional image and was in very good agreement with the calculated value based on magnetic flux measurements. Combined magnetic and physical characterizations suggest that the dead layer thickness saturates at the initial stage of the plasma etching and magnetic property remained unchanged with increasing etching duration upon formation of the dead layer.

• OSTI ID: 21476202
• Journal Information: Journal of Applied Physics, Vol. 107, Issue 9; Conference: 11. joint MMM-Intermag conference, Washington, DC (United States), 18-22 Jan 2010; Other Information: DOI: 10.1063/1.3356231; (c) 2010 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHLORINE
CRYSTALS
ETCHING
FLUORINE
IRON ALLOYS
LAYERS
MAGNETIC FLUX
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MILLING
NICKEL ALLOYS
ORIENTATION
OXYGEN
SPUTTERING
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
ALLOYS
COHERENT SCATTERING
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
HALOGENS
MACHINING
MICROSCOPY
NONMETALS
PHYSICAL PROPERTIES
SCATTERING
SURFACE FINISHING
TRANSITION ELEMENT ALLOYS