SNMS of Magnetic Storage Materials
Depth profiling and quantified composition of alloys using SNMS.
SNMS provides excellent depth resolution and quantification to analyse the layer structure of the hard disc head material and the active region of the platter surface itself.
Sputtered Neutral Mass Spectrometry
Sputtered Neutral mass Spectrometry separates the ionisation event from the sputtering and thus overcomes the matrix effect which makes high concentration quantification difficult in conventional SIMS analysis.
The MAXIM spectrometer uses a high efficiency electron impact ioniser to detect the sputtered neutral flux after secondary ions have been removed by means of an external deflector.
With no significant matrix effect there is no need for matrix matched reference materials, as is the case with SIMS, and easily available alloys may be used to determine global sensitivity factors.
Low energy beams give improved depth resolution but can also induce surface topography. A directional jet of pure oxygen is provided over the
sample surface, fully oxidising the surface via a stainless steel capillary.
The gives enhancements in sensitivity for the analysis of electropositive species such as metals and semiconductor dopants, as well as reductions in surface roughness in low beam energy, high depth resolution analyses.
The examples show the improvements in surface topography given by the use of the localised oxygen flood in a 3.6 nm multilayer Si/Fe sample.
Without oxygen flood depth resolution decays (Left). With oxygen flood depth resolution is maintained (Right).