scholarly journals A Differentially-Pumped Low-Energy Ion-Beam System for an Ultra-High Vacuum (UHV) Atom-Probe Field-Ion Microscope

1978 ◽  
Author(s):  
Jun Amano ◽  
David N. Seidman
Vacuum ◽  
1978 ◽  
Vol 28 (12) ◽  
pp. 543-545 ◽  
Author(s):  
Alfred Wagner ◽  
Thomas M. Hall ◽  
David N. Seidman

1996 ◽  
Vol 438 ◽  
Author(s):  
N. Tsubouchi ◽  
Y. Horino ◽  
B. Enders ◽  
A. Chayahara ◽  
A. Kinomura ◽  
...  

AbstractUsing a newly developed ion beam apparatus, PANDA (Positive And Negative ions Deposition Apparatus), carbon nitride films were prepared by simultaneous deposition of mass-analyzed low energy positive and negative ions such as C2-, N+, under ultra high vacuum conditions, in the order of 10−6 Pa on silicon wafer. The ion energy was varied from 50 to 400 eV. The film properties as a function of their beam energy were evaluated by Rutherford Backscattering Spectrometry (RBS), Fourier Transform Infrared spectroscopy (FTIR) and Raman scattering. From the results, it is suggested that the C-N triple bond contents in films depends on nitrogen ion energy.


A computer-controlled atom probe time-of-flight mass spectrometer-field ion microscope system has been developed which permits chemical microanalysis of metals and alloys with approximately 1 nm spatial resolution, good quantitative accuracy and excellent sensitivity for the detection of trace elements. The mass resolution is sufficient to separate adjacent isotopes of the transition elements, and the detection efficiency for single atoms is approximately 90 %. Operation is carried out under ultra-high vacuum conditions to minimize background noise levels. Detection of local concentrations of trace elements and impurities of the order of 0.1 at. % is routinely obtained with this instrument. An additional analytical facility, termed an imaging field desorption atom probe, (i.f.d.a.p.) has also recently been constructed. This produces a picture of the spatial distribution of a selected chemical element over the whole of the imaged region of the field-ion specimen; the information obtained is essentially complementary to that from the conventional time-of-flight atom probe.


Author(s):  
Amanda K. Petford-Long ◽  
A. Cerezo ◽  
M.G. Hetherington

The fabrication of multilayer films (MLF) with layer thicknesses down to one monolayer has led to the development of materials with unique properties not found in bulk materials. The properties of interest depend critically on the structure and composition of the films, with the interfacial regions between the layers being of particular importance. There are a number of magnetic MLF systems based on Co, several of which have potential applications as perpendicular magnetic (e.g Co/Cr) or magneto-optic (e.g. Co/Pt) recording media. Of particular concern are the effects of parameters such as crystallographic texture and interface roughness, which are determined by the fabrication conditions, on magnetic properties and structure.In this study we have fabricated Co-based MLF by UHV thermal evaporation in the prechamber of an atom probe field-ion microscope (AP). The multilayers were deposited simultaneously onto cobalt field-ion specimens (for AP and position-sensitive atom probe (POSAP) microanalysis without exposure to atmosphere) and onto the flat (001) surface of oxidised silicon wafers (for subsequent study in cross-section using high-resolution electron microscopy (HREM) in a JEOL 4000EX. Deposi-tion was from W filaments loaded with material in the form of wire (Co, Fe, Ni, Pt and Au) or flakes (Cr). The base pressure in the chamber was around 8×10−8 torr during deposition with a typical deposition rate of 0.05 - 0.2nm/s.


1996 ◽  
Vol 438 ◽  
Author(s):  
R. L. C. Wu ◽  
W. Lanter

AbstractAn ultra high vacuum ion beam system, consisting of a 20 cm diameter Rf excilted (13.56 MHz) ion gun and a four-axis substrate scanner, has been used to modify large surfaces (up to 1000 cm2) of various materials, including; infrared windows, silicon nitride, polycrystalline diamond, 304 and 316 stainless steels, 440C and M50 steels, aluminum alloys, and polycarbonates; by depositing different chemical compositions of diamond-like carbon films. The influences of ion energy, Rf power, gas composition (H2/CH4 , Ar/CH4 and O2/CH4/H2), on the diamond-like carbon characteristics has been studied. Particular attention was focused on adhesion, environmental effects, IR(3–12 μm) transmission, coefficient of friction, and wear factors under spacelike environments of diamond-like carbon films on various substrates. A quadrupole mass spectrometer was utilized to monitor the ion beam composition for quality control and process optimization.


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