Roughness Effects During Focused Ion Beam Repair of X-Ray Masks with Polycrystalline Tungsten Absorbers

1992 ◽  
Vol 279 ◽  
Author(s):  
R. R. Kola ◽  
G. K. Celler ◽  
L R. Harriott
Keyword(s):  
Material Removal ◽  
Etch Rate ◽  
Focused Ion Beam ◽  
Removal Rate ◽  
Ion Beam ◽  
Sidewall Roughness ◽  
X Ray ◽  
Polycrystalline Tungsten ◽  
Absorber Material ◽  
Defect Repair

ABSTRACTTungsten is emerging as the absorber material of choice for x-ray masks due to recent advances in the deposition of low stress films. For a practical technology, the masks must be free from defects. These defects may be in the form of excess or missing absorber. Finely focused ion beams have been used for defect repair on x-ray masks, both for removal of excess absorber material by physical sputtering and for addition of absorber material by ion-induced deposition. The eifect of ion channeling in polycrystalline tungsten films is spatially nonuniform material removal during sputtering. Different grains will have significantly different sputtering yields, depending on their orientation with respect to the direction of the ion beam. The repaired features then suffer from roughness on the bottoms and sidewalls of the sputter craters. We have investigated the use of XeF2 assisted sputtering with a 20 keV Ga+ focused ion beam to reduce this roughness. The chemical etching component of the material removal lessens the directional dependence and therefore the roughness during defect repair. It was also found that chromium etch rate was reduced in the presence of XeF2 gas while the etch rate of W was enhanced so that the removal rate of Cr is much less than that of W. We can take advantage of this etch selectivity by using a thin Cr layer under the W absorber as an etch stop layer to eliminate the roughness at the bottom of the features and a thin layer of Cr on top of the W as an etch mask for reducing the sidewall roughness.

scholarly journals Focused Ion Beam Milling of Single-Crystal Sapphire with A-, C-, and M-Orientations

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2871
Author(s):  
Qiuling Wen ◽  
Xinyu Wei ◽  
Feng Jiang ◽  
Jing Lu ◽  
Xipeng Xu
Keyword(s):  
Single Crystal ◽  
Surface Quality ◽  
Material Removal ◽  
Focused Ion Beam ◽  
Removal Rate ◽  
Ion Beam ◽  
Crystal Orientations ◽  
Aluminum Ions ◽  
Single Crystal Sapphire

Sapphire substrates with different crystal orientations are widely used in optoelectronic applications. In this work, focused ion beam (FIB) milling of single-crystal sapphire with A-, C-, and M-orientations was performed. The material removal rate (MRR) and surface roughness (Sa) of sapphire with the three crystal orientations after FIB etching were derived. The experimental results show that: The MRR of A-plane sapphire is slightly higher than that of C-plane and M-plane sapphires; the Sa of A-plane sapphire after FIB treatment is the smallest among the three different crystal orientations. These results imply that A-plane sapphire allows easier material removal during FIB milling compared with C-plane and M-plane sapphires. Moreover, the surface quality of A-plane sapphire after FIB milling is better than that of C-plane and M-plane sapphires. The theoretical calculation results show that the removal energy of aluminum ions and oxygen ions per square nanometer on the outermost surface of A-plane sapphire is the smallest. This also implies that material is more easily removed from the surface of A-plane sapphire than the surface of C-plane and M-plane sapphires by FIB milling. In addition, it is also found that higher MRR leads to lower Sa and better surface quality of sapphire for FIB etching.

A Preliminary Study on Machinability of Polymethylmethacrylate (PMMA)/Multi-Walled Carbon Nanotube (MWCNT) Nanocomposites in Focused Ion Beam Micromachining

2011 ◽  
Author(s):  
Pengfei Li ◽  
Wei Xue ◽  
Dave Dae-Wook Kim ◽  
Young-Bin Park
Keyword(s):  
Carbon Nanotube ◽  
Material Removal Rate ◽  
Soft Lithography ◽  
Material Removal ◽  
Focused Ion Beam ◽  
Removal Rate ◽  
Ion Beam ◽  
Input Current ◽  
Multi Walled Carbon Nanotube ◽  
Solution Casting Method

This experimental study investigated the machinability of polymethylmethacrylate (PMMA)/multi-walled carbon nanotube (MWCNT) nanocomposites with 20 wt% MWCNTs in focused ion beam (FIB) micromachining. PMMA/MWCNT nanocomposites were fabricated using a solution casting method, in which PMMA and MWCNTs were dispersed in a solvent by ultrasonication. Microscale rectangular pockets were created on the PMMA/MWCNT nanocomposites to study the material removal mechanism in FIB. Effects of FIB input current and the ion beam overlap parameter (overlap %) on the material removal rate and geometric accuracy were studied. It was observed that the material removal rate increased with increasing input current and decreasing overlap %. Soft lithography was used to translate the ion-milled pockets on PMMA/MWCNT nanocomposites into microscale posts on polydimethylsiloxane (PDMS) for accurate measurement of the pocket geometries. A Scanning Electron Microscope (SEM) was used to investigate the characteristics of the micromachined features, nanocomposite surfaces, and replicated PDMS patterns. Our results demonstrated an effective method to produce microscale patterns on MWCNT-based nanocomposites.

3D Observation of Elemental Distribution of Si-Device using a Dedicated FIB/STEM System

2005 ◽  
Author(s):  
T. Yaguchi ◽  
M. Konno ◽  
T. Kamino ◽  
M. Ogasawara ◽  
K. Kaji ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Three Dimensional ◽  
Elemental Distribution ◽  
Multivariate Statistical ◽  
X Ray ◽  
Sample Rotation ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Elemental Maps

Abstract A technique for preparation of a pillar shaped sample and its multi-directional observation of the sample using a focused ion beam (FIB) / scanning transmission electron microscopy (STEM) system has been developed. The system employs an FIB/STEM compatible sample rotation holder with a specially designed rotation mechanism, which allows the sample to be rotated 360 degrees [1-3]. This technique was used for the three dimensional (3D) elemental mapping of a contact plug of a Si device in 90 nm technology. A specimen containing a contact plug was shaped to a pillar sample with a cross section of 200 nm x 200 nm and a 5 um length. Elemental analysis was performed with a 200 kV HD-2300 STEM equipped with the EDAX genesis Energy dispersive X-ray spectroscopy (EDX) system. Spectrum imaging combined with multivariate statistical analysis (MSA) [4, 5] was used to enhance the weak X-ray signals of the doped area, which contain a low concentration of As-K. The distributions of elements, especially the dopant As, were successfully enhanced by MSA. The elemental maps were .. reconstructed from the maps.

Oxidation of Alloy-X in Subcritical, Transition, and Supercritical Water

CORROSION ◽  
10.5006/3881 ◽  
2021 ◽  
Author(s):  
Zachary Karmiol ◽  
Dev Chidambaram
Keyword(s):  
Supercritical Water ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Elevated Temperatures ◽  
Subcritical Water ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Based Superalloy ◽  
Before And After

This work investigates the oxidation of a nickel based superalloy, namely Alloy X, in water at elevated temperatures: subcritical water at 261°C and 27 MPa, the transition between subcritical and supercritical water at 374°C and 27 MPa, and supercritical water at 380°C and 27 MPa for 100 hours. The morphology of the sample surfaces were studied using scanning electron microscopy coupled with focused ion beam milling, and the surface chemistry was investigated using X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy before and after exposure studies. Surfaces of all samples were identified to comprise of a ferrite spinel containing aluminum.

High Conductivity FIB Deposited Metal

1995 ◽  
Vol 396 ◽  
Author(s):  
P.G. Blauner ◽  
A. Wagner
Keyword(s):  
Focused Ion Beam ◽  
High Efficiency ◽  
Ion Beam ◽  
Deposition Process ◽  
Gold Deposition ◽  
X Ray ◽  
Annealing Step ◽  
Deposited Metal ◽  
Major Application ◽  
Deposition Processes

AbstractThe ion beam induced metal deposition processes now employed by commercial focused ion beam (FIB) tools all demonstrate less than optimal characteristics for use in circuit repair, a major application of these tools. In particular, the processes have low efficiencies, the metals produced have poor conductivity, and some form of clean up is generally required to remove excess material surrounding the repair site. The gold deposition process developed for x-ray mask repair, in contrast, exhibits efficiencies 10-50 times higher with significantly less material deposited in unwanted areas. Unfortunately, the conductivity of the gold is even poorer than that of materials now used for FIB circuit repair.In this paper, an annealing step which improves the conductivity of FIB deposited Au is described. Results are presented demonstrating resistivities of 5-15 μΩ-cm while maintaining the high efficiency of the gold deposition process. The suitability of the process for use in FIB circuit repair is discussed.

Imaging of retina cellular and subcellular structures using ptychographic hard X-ray tomography

2021 ◽  
Vol 134 (19) ◽  
Author(s):  
Valerie Panneels ◽  
Ana Diaz ◽  
Cornelia Imsand ◽  
Manuel Guizar-Sicairos ◽  
Elisabeth Müller ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Plexiform Layer ◽  
Wild Type Mouse ◽  
Small Region ◽  
Mouse Retina ◽  
Imaging Method ◽  
Scanning Method ◽  
X Ray ◽  
Correlative Imaging

ABSTRACT Ptychographic hard X-ray computed tomography (PXCT) is a recent method allowing imaging with quantitative electron-density contrast. Here, we imaged, at cryogenic temperature and without sectioning, cellular and subcellular structures of a chemically fixed and stained wild-type mouse retina, including axons and synapses, with complete isotropic 3D information over tens of microns. Comparison with tomograms of degenerative retina from a mouse model of retinitis pigmentosa illustrates the potential of this method for analyzing disease processes like neurodegeneration at sub-200 nm resolution. As a non-destructive imaging method, PXCT is very suitable for correlative imaging. Within the outer plexiform layer containing the photoreceptor synapses, we identified somatic synapses. We used a small region inside the X-ray-imaged sample for further high-resolution focused ion beam/scanning electron microscope tomography. The subcellular structures of synapses obtained with the X-ray technique matched the electron microscopy data, demonstrating that PXCT is a powerful scanning method for tissue volumes of more than 60 cells and sensitive enough for identification of regions as small as 200 nm, which remain available for further structural and biochemical investigations.

scholarly journals Artifacts from manganese reduction in rock samples prepared by focused ion beam (FIB) slicing for X-ray microspectroscopy

2019 ◽  
Vol 8 (1) ◽  
pp. 97-111
Author(s):  
Dorothea S. Macholdt ◽  
Jan-David Förster ◽  
Maren Müller ◽  
Bettina Weber ◽  
Michael Kappl ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Oxidation States ◽  
X Ray ◽  
Scientific Debate ◽  
Rock Samples ◽  
Valence States ◽  
Scanning Transmission ◽  
Visualization Techniques

Abstract. The spatial distribution of transition metal valence states is of broad interest in the microanalysis of geological and environmental samples. An example is rock varnish, a natural manganese (Mn)-rich rock coating, whose genesis mechanism remains a subject of scientific debate. We conducted scanning transmission X-ray microscopy with near-edge X-ray absorption fine-structure spectroscopy (STXM-NEXAFS) measurements of the abundance and spatial distribution of different Mn oxidation states within the nano- to micrometer thick varnish crusts. Such microanalytical measurements of thin and hard rock crusts require sample preparation with minimal contamination risk. Focused ion beam (FIB) slicing was used to obtain ∼100–1000 nm thin wedge-shaped slices of the samples for STXM, using standard parameters. However, while this preparation is suitable for investigating element distributions and structures in rock samples, we observed artifactual modifications of the Mn oxidation states at the surfaces of the FIB slices. Our results suggest that the preparation causes a reduction of Mn4+ to Mn2+. We draw attention to this issue, since FIB slicing, scanning electron microscopy (SEM) imaging, and other preparation and visualization techniques operating in the kilo-electron-volt range are well-established in geosciences, but researchers are often unaware of the potential for the reduction of Mn and possibly other elements in the samples.

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