Aspects of high-resolution imaging with a scanning ion microprobe

1986 ◽  
Vol 44 ◽  
pp. 750-751
Author(s):  
R. Levi-Setti ◽  
J. M. Chabala ◽  
Y. L. Wang
Keyword(s):  
Metal Ion ◽  
Secondary Ion Mass Spectrometry ◽  
Chromatic Aberration ◽  
Ion Source ◽  
Ion Microprobe ◽  
Emission Pattern ◽  
Intrinsic Resolution ◽  
Resolution Imaging ◽  
20 Nm ◽  
Secondary Ion

We have shown the feasibility of 20 nm lateral resolution in both topographic and elemental imaging using probes of this size from a liquid metal ion source (LMIS) scanning ion microprobe (SIM). This performance, which approaches the intrinsic resolution limits of secondary ion mass spectrometry (SIMS), was attained by limiting the size of the beam defining aperture (5μm) to subtend a semiangle at the source of 0.16 mr. The ensuing probe current, in our chromatic-aberration limited optical system, was 1.6 pA with Ga+ or In+ sources. Although unique applications of such low current probes have been demonstrated,) the stringent alignment requirements which they imposed made their routine use impractical. For instance, the occasional tendency of the LMIS to shift its emission pattern caused severe misalignment problems.

Secondary ion imaging microanalysis

1989 ◽  
Vol 47 ◽  
pp. 8-9
Author(s):  
R. Levi-Setti ◽  
J. M. Chabala ◽  
C Girod-Hallegot ◽  
P. Hallegot ◽  
Y. L. Wang
Keyword(s):  
Metal Ion ◽  
Secondary Ion Mass Spectrometry ◽  
Sample Surface ◽  
Biological Tissues ◽  
Ion Source ◽  
Ion Imaging ◽  
Research Areas ◽  
Interdisciplinary Problems ◽  
20 Nm ◽  
Secondary Ion

The goals of high spatial resolution and high elemental sensitivity in the imaging microanalysis of biological tissues and materials have, to a large extent, been attained by using the method of secondary ion mass spectrometry (SIMS) following bombardment of a sample surface by a focused beam of heavy ions. The instrument that we will discuss and which has achieved these goals is a scanning ion microprobe originally developed in collaboration with Hughes Research Laboratories (UC-HRL SIM). It utilizes a 40-60 keV Ga+ probe, extracted from a point-like liquid metal ion source, that can be focused to a spot as small as 20 nm in diameter. During the past five years, much effort has been devoted to a reappraisal of well known SIMS methodologies in regard to their applicability to a range of lateral resolution (20-1000 nm) previously unexplored. Furthermore, of particular concern has been the identification of research areas whose demands could most profitably be matched by the performance of this new class of microprobes. The results of this effort are contained in over 21 topical publications and 14 review articles covering both instrumental aspects of our development and applications to a variety of interdisciplinary problems.

Microscale Elemental Imaging of Semiconductor Materials Using Focused Ion Beam Sims

1998 ◽  
Vol 4 (S2) ◽  
pp. 650-651 ◽  
Author(s):  
F. A. Stevie ◽  
S. W. Downey ◽  
S. Brown ◽  
T. Shofner ◽  
M. Decker ◽  
...  
Keyword(s):  
Metal Ion ◽  
Focused Ion Beam ◽  
Secondary Ion Mass Spectrometry ◽  
Ion Beam ◽  
Semiconductor Industry ◽  
Ion Source ◽  
Comb Structure ◽  
Types Of Information ◽  
20 Nm ◽  
Secondary Ion

The semiconductor industry demands elemental information from ever smaller regions. Two types of information in demand are two dimensional dopant profiles for the MOS transisitor and identification of particles as small as 30 nm diameter. The work of Levi-Setti and others resulted in liquid metal ion source (LMIS) instruments that provided secondary ion mass spectrometry (SIMS) images using Ga+ beams with 20 nm lateral resolution. It is now possible to purchase focused ion beam (FIB) systems with 5 nm beam capability and SIMS detection.The application of LMIS SIMS to meet semiconductor demands has been pursued in our laboratory with a FEI-800 FIB. SIMS imaging of semiconductor patterns after etch has shown the ability to identify boron and carbon contamination. Figure 1 shows boron in a comb structure after a BC13 etch. The boron can be shown to be removed by a cleaning step.

Cesium liquid metal ion source for secondary ion mass spectrometry

1994 ◽  
Vol 65 (7) ◽  
pp. 2276-2280 ◽  
Author(s):  
Kaoru Umemura ◽  
Hiroyasu Shichi ◽  
Setsuo Nomura
Keyword(s):  
Mass Spectrometry ◽  
Liquid Metal ◽  
Metal Ion ◽  
Secondary Ion Mass Spectrometry ◽  
Ion Source ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

Negative metal‐ion source for secondary‐ion mass spectrometry

1993 ◽  
Vol 64 (5) ◽  
pp. 1146-1149 ◽  
Author(s):  
Hisayoshi Yurimoto ◽  
Yoshiharu Mori ◽  
Hironori Yamamoto
Keyword(s):  
Mass Spectrometry ◽  
Metal Ion ◽  
Secondary Ion Mass Spectrometry ◽  
Ion Source ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

scholarly journals High Spatial Resolution Time-of-Flight Secondary Ion Mass Spectrometry for the Masses: A Novel Orthogonal ToF FIB-SIMS Instrument withIn SituAFM

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
James A. Whitby ◽  
Fredrik Östlund ◽  
Peter Horvath ◽  
Mihai Gabureac ◽  
Jessica L. Riesterer ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Metal Ion ◽  
Secondary Ion Mass Spectrometry ◽  
High Spatial Resolution ◽  
Collection Efficiency ◽  
Ion Beam ◽  
Time Of Flight ◽  
Ion Source ◽  
New Instrument ◽  
Secondary Ion

We describe the design and performance of an orthogonal time-of-flight (TOF) secondary ion mass spectrometer that can be retrofitted to existing focused ion beam (FIB) instruments. In particular, a simple interface has been developed for FIB/SEM instruments from the manufacturer Tescan. Orthogonal extraction to the mass analyser obviates the need to pulse the primary ion beam and does not require the use of monoisotopic gallium to preserve mass resolution. The high-duty cycle and reasonable collection efficiency of the new instrument combined with the high spatial resolution of a gallium liquid metal ion source allow chemical observation of features smaller than 50 nm. We have also demonstrated the integration of a scanning probe microscope (SPM) operated as an atomic force microscope (AFM) within the FIB/SEM-SIMS chamber. This provides roughness information, and will also allow true three dimensional chemical images to be reconstructed from SIMS measurements.

Imaging of Al-Li-Cu alloys with a Scanning Ion Microprobe

1990 ◽  
Vol 48 (2) ◽  
pp. 314-315
Author(s):  
K.K. Soni ◽  
D.B. Williams ◽  
J.M. Chabala ◽  
R. Levi-Setti ◽  
D.E. Newbury
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Equilibrium Phase ◽  
Icosahedral Symmetry ◽  
Ion Microprobe ◽  
X Ray ◽  
Cu Alloys ◽  
Two Phases ◽  
The University ◽  
Secondary Ion

In contrast to the inability of x-ray microanalysis to detect Li, secondary ion mass spectrometry (SIMS) generates a very strong Li+ signal. The latter’s potential was recently exploited by Williams et al. in the study of binary Al-Li alloys. The present study of Al-Li-Cu was done using the high resolution scanning ion microprobe (SIM) at the University of Chicago (UC). The UC SIM employs a 40 keV, ∼70 nm diameter Ga+ probe extracted from a liquid Ga source, which is scanned over areas smaller than 160×160 μm2 using a 512×512 raster. During this experiment, the sample was held at 2 × 10-8 torr.In the Al-Li-Cu system, two phases of major importance are T1 and T2, with nominal compositions of Al2LiCu and Al6Li3Cu respectively. In commercial alloys, T1 develops a plate-like structure with a thickness <∼2 nm and is therefore inaccessible to conventional microanalytical techniques. T2 is the equilibrium phase with apparent icosahedral symmetry and its presence is undesirable in industrial alloys.

Fluidized Catalytic Cracking Catalyst Microstructure as Determined by A Scanning Ion Microprobe

1990 ◽  
Vol 48 (2) ◽  
pp. 302-303
Author(s):  
J.K. Lampert ◽  
G.S. Koermer ◽  
J.M. Macaoy ◽  
J.M. Chabala ◽  
R. Levi-Setti
Keyword(s):  
Catalytic Cracking ◽  
Secondary Ion Mass Spectrometry ◽  
Fuel Oil ◽  
Ion Microprobe ◽  
Fluidized Catalytic Cracking ◽  
Ion Probe ◽  
Silica Alumina ◽  
Resolution Imaging ◽  
The University ◽  
High Spatial Resolution Imaging

We have used high spatial resolution imaging secondary ion mass spectrometry (SIMS) to differentiate mineralogical phases and to investigate chemical segregations in fluidized catalytic cracking (FCC) catalyst particles. The oil industry relies on heterogeneous catalysis using these catalysts to convert heavy hydrocarbon fractions into high quality gasoline and fuel oil components. Catalyst performance is strongly influenced by catalyst microstructure and composition, with different chemical reactions occurring at specific types of sites within the particle. The zeolitic portions of the particle, where the majority of the oil conversion occurs, can be clearly distinguished from the surrounding silica-alumina matrix in analytical SIMS images.The University of Chicago scanning ion microprobe (SIM) employed in this study has been described previously. For these analyses, the instrument was operated with a 40 keV, 10 pA Ga+ primary ion probe focused to a 30 nm FWHM spot. Elemental SIMS maps were obtained from 10×10 μm2 areas in times not exceeding 524s.

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