Focused such sample preparation in order to

Focused Ion Beam (FIB) is a powerful, versatile, and well-established method
for nanofabrication using ion beam lithography without masks and resists. It
can precisely machine 3D structures on mesoscopic and nanometer sclaes. With
FIB, it is possible to extract the specimens in desired pattern and from very
speci c locations. Ion implantation occurs during the ion beam exposure and
causes the amorphization of crystal structure depending on the degree of im-
plantation. The amorphization or the damage caused to the ion beam can be
useful or disadvantageous con de in the hindsight application and goal of the
study 1. The milling of samples for transmission electron microscope (TEM)
is well known application of FIB among other utilizations. The low-kV FIB
conditions are very useful for such sample preparation in order to minimize ion
damage and to make high quality specimens. For example, the ion implanta-
tion is used to improve many electronic devices, and batteries 2, and on the


other hand, it may damage the crystalline, mechanical and magnetic proper-
ties. Gallium ions are most commonly used in the FIB ion beams, among other
like hellium ion, argon ion etc. The milling and sputtering rates depends on
the material properties and beam charging (current, dwell time, and spot size)
on the material surface.

Many systematic studies about the ion damage (Ga+, Ar+, Au+, He+,
Si+, Cu+, etc) to the various material (metals, semiconductors, magnetic ma-
terials, biological specimens and others) has been reported in literature, and
well studied with various techniques and methods (depending on the properties
under observation) 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13. The stoichiometric e ects
can be observed after annealing the ion implantation 4. The damage recov-
ery is possible in some cases depending upon the amorphization and annealing
procedures 5. The ion irradiation can increase the chemical reactivity of the
surface because of induced defects, adsorption, and catalysis 6. FIB has also
been used for etching (using molecular chlorine) as maskless and resistless re-
moval of silicon and can also be used to remove FIB-induced crystal damage
and ion implantation 10.

The ion damage in YIG has been reported with various ion irradiation and
implantation methods. Thin epitaxially grown YIG lms irradiated with swift
heavy ions showed change in crystalline, electronic, and magnetic phases 14,
15. Coexistence of crystalline and disordered phases has also been reported 14,
16. Large etch selectivity is also observed when YIG was implanted with ion
17. Ion induced thermal instability and phonon modes behaviour were studied
with Raman spectroscopy for YIG 18, 19. Structural damage and swelling as
a result of ion damage has been studied via scanning force microscopy 20, and
TEM 21. The spin wave resonance study of YIG sample via ion implantation
has been executed to obtain resonance spectra 22.

Microscopy includes the optical microscopy (conventional light microscopy,
uorescence microscopy, confocal/multiphoton microscopy, etc), scanning


probe microscopy (scanning tunneling microscopy (STM), atomic force mi-
croscopy (AFM), etc), and electron microscopy (scanning electron microscopy
(SEM), transmission electron microscopy (TEM), Focus ion beam microscopy
(FIB), etc). A TEM uses electron gun, electric and magnetic lenses, and aper-
tures to control the electron beam. Detectors at various locations inside TEM
receive the electron signals and produce the TEM images and di raction pat-
terns of desired output. The electron beam transmits through the ultrathin
sample and a combination of objectives, apertures and detectors produce de-
sired results. Information regarding structure, morphology and composition
can be extracted using TEM 23. In-situ irradiation in TEM gives the time
resolved evolution of the damage and other time-domain information can also
be extracted 24.

The sample preparation in FIB inherently involves damaging the sample
and thus degrade the sample to an extent. The ion damage artifacts related to
the TEM sample preparation method are well understood 13. This chapter
discuss the ion beam induced damage and artifacts in YIG and silicon nitride.
The ion damage is studied using TEM imaging and di raction techniques. 


I'm Mary!

Would you like to get a custom essay? How about receiving a customized one?

Check it out