Surface Modification Energized by FIB: The Influence of Etch Rates & Aspect Ratio on Ripple Wavelengths

2006 ◽  
Vol 960 ◽  
Author(s):  
Warren MoberlyChan
Keyword(s):  
Aspect Ratio ◽  
Self Assembly ◽  
Focused Ion Beam ◽  
Process Development ◽  
Ion Beam ◽  
Natural Diamond ◽  
Single Crystal Silicon ◽  
Nanometer Scale ◽  
Crystal Silicon ◽  
Etch Rates

ABSTRACTIon beams have been used to modify surface topography, producing nanometer-scale modulations (and even subnanometer ripples in this work) that have potential uses ranging from designing self-assembly structures, to controlling stiction of micromachined surfaces, to providing imprint templates for patterned media. Modern computer-controlled Focused Ion Beam tools enable alternating submicron patterned zones of such ion-eroded surfaces, as well as dramatically increasing the rate of ion beam processing. The DualBeam FIB/SEM also expedites process development while minimizing the use of materials that may be precious (Diamond) and/or produce hazardous byproducts (Beryllium). A FIB engineer can prototype a 3-by-3-by-3 matrix of variables in tens of minutes and consume as little as zeptoliters of material; whereas traditional ion beam processing would require tens of days and tens of precious wafers. Saturation wavelengths have been reported for ripples on materials such as single crystal silicon or diamond (∼200nm); however this work achieves wavelengths >400nm on natural diamond. Conversely, Be can provide a stable and ordered 2-dimensional array of <40nm periodicity. Also ripples <0.4nm are fabricated on carbon-base surfaces, and these quantized picostructures are measured by HR-TEM and electron diffraction. Rippling is a function of material, ion beam, and angle; but is also controlled by chemical environment, redeposition, and aspect ratio. Ideally a material has a constant yield (atoms sputtered off per incident ion); however, pragmatic FIB processes, coupled with the direct metrological feedback in a DualBeam tool, reveal etch rates do not remain constant for nanometer-scale processing. Control of rippling requires controlled metrology, and robust software tools are developed to enhance metrology. In situ monitoring of the influence of aspect ratio and redeposition at the micron scale correlates to the rippling fundamentals that occur at the nanometer scale and are controlled by the boundary conditions of FIB processing.

scholarly journals Identification of microscopic uranium particles using fission tracks in nuclear solid-state detectors

2018 ◽  
Vol 48 ◽  
pp. 1860108
Author(s):  
Kristína Sihelská ◽  
Klára Řezanková ◽  
Petr Homola ◽  
František Sus ◽  
Jan Lorinčík
Keyword(s):  
Silicon Substrate ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Single Crystal Silicon ◽  
Dust Particles ◽  
Particle Analysis ◽  
Spectrometric Analysis ◽  
Crystal Silicon ◽  
Modified Method ◽  
Research Goal

Improved environmental-particle analysis for safeguards is a continuing research goal. In this paper, we propose a modified method of fission-track analysis, employing the focused ion-beam (FIB) technique and using a single-crystal silicon substrate to carry dust particles. The use of a silicon substrate may eliminate the need to relocate identified particles of interest from the particle carrier to another substrate for mass-spectrometric analysis. FIB–SEM and SIMS were used to evaluate the efficiency of the proposed FTA method.

scholarly journals An Investigation into Fracture of Multi-Crystalline Silicon

2009 ◽  
Vol 156-158 ◽  
pp. 55-60
Author(s):  
B.R. Mansfield ◽  
David E.J. Armstrong ◽  
Peter R. Wilshaw ◽  
John D. Murphy
Keyword(s):  
Grain Boundaries ◽  
Focused Ion Beam ◽  
Crystalline Silicon ◽  
Ion Beam ◽  
Single Crystal Silicon ◽  
Front Surface ◽  
Beam Width ◽  
Relative Strength ◽  
Transgranular Fracture ◽  
Crystal Silicon

As the thickness of multi-crystalline silicon solar cells continues to reduce, understanding the mechanical properties of the material is of increasing importance. In this study, a variety of techniques are used to study multi-crystalline silicon. Fracture tests are performed using four- and three-point bending. The fracture stress of as-sawn material reduces with increasing beam width and is increased in beams with a polished front surface. This indicates that fracture initiates from surface flaws. Modifications to standard fracture testing, including testing under liquid, are made so that beams fracture into just two pieces. By determining the crystallography either side of the location of fracture, multi-crystalline silicon was found to fail by transgranular fracture in the samples studied. Further evidence for this is gained from indentation experiments at grain boundaries. In order to understand the relative strength of grain boundaries, new approaches need to be considered. Therefore, a novel micromechanical technique, which enables individual grain boundaries to be studied, has started to be applied to multi-crystalline silicon. A focused ion beam is used to mill micron-scale cantilevers across notched grain boundaries, which are then loaded to fracture using the tip of a nanoindenter. The technique is shown to reproduce the known fracture toughness of {110} planes in single-crystal silicon, giving a value of 0.7 ± 0.3MPam1/2. Preliminary results are presented for fracture of multi-crystalline silicon.

Influence of Specimen Size and Sub-Micron Notch on The Fracture Behavior of Single Crystal Silicon Microelements and Nanoscopic Afm Damage Evaluation

1998 ◽  
Vol 546 ◽  
Author(s):  
Kohji Minoshima ◽  
Shigemichi Inoue ◽  
Tomota Terada ◽  
Kenjiro Komai
Keyword(s):  
Single Crystal ◽  
Fracture Strength ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Single Crystal Silicon ◽  
Fatigue Loading ◽  
Sample Surface ◽  
Specimen Size ◽  
Fracture Mechanisms ◽  
Crystal Silicon

AbstractSimple bending tests of single-crystal silicon microelements fabricated by photoetching were performed. Silicon microelements deform elastically until final catastrophic failure, showing a brittle nature. The fracture strength increases with a decrease in specimen size, and the maximum strength reaches about 8 GPa. A Focused ion beam was used to machine a sub-µm deep notch. Such a small notch decreases the fracture strength of a microelement. Some fatigue tests were conducted in laboratory air and in distilled water: water reduces the strength of microelement under fatigue loading. Fracture surface and sample surface were closely examined with a scanning electron microscope and an atomic force microscope, and the fracture mechanisms are discussed from the nanoscopic points of view.

scholarly journals Microstructure and Mechanical Properties of Electroplated Cu Thin Films

2000 ◽  
Vol 649 ◽  
Author(s):  
A.A. Volinsky ◽  
J. Vella ◽  
I.S. Adhihetty ◽  
V. Sarihan ◽  
L. Mercado ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Single Crystal Silicon ◽  
Tensile Tests ◽  
Crystal Silicon ◽  
Cu Films ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTCopper films of different thicknesses of 0.2, 0.5, 1 and 2 microns were electroplated on top of the adhesion-promoting barrier layers on <100> single crystal silicon wafers. Controlled Cu grain growth was achieved by annealing films in vacuum.The Cu film microstructure was characterized using Atomic Force Microscopy and Focused Ion Beam Microscopy. Elastic modulus of 110 to 130 GPa and hardness of 1 to 1.6 GPa were measured using the continuous stiffness option (CSM) of the Nanoindenter XP. Thicker films appeared to be softer in terms of the lower modulus and hardness, exhibiting a classical Hall-Petch relationship between the yield stress and grain size. Lower elastic modulus of thicker films is due to the higher porosity and partially due to the surface roughness. Comparison between the mechanical properties of films on the substrates obtained by nanoindentation and tensile tests of the freestanding Cu films is made.

Fluorocarbon Precursor for High Aspect Ratio via Milling in Focused Ion Beam Modification of Integrated Circuits

2004 ◽  
Author(s):  
Valery Ray
Keyword(s):  
Side Effects ◽  
Aspect Ratio ◽  
Integrated Circuits ◽  
High Aspect Ratio ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Enabling Technology ◽  
Si Substrate ◽  
Ion Beam Modification ◽  
The Past

Abstract Gas Assisted Etching (GAE) is the enabling technology for High Aspect Ratio (HAR) circuit access via milling in Focused Ion Beam (FIB) circuit modification. Metal interconnect layers of microelectronic Integrated Circuits (ICs) are separated by Inter-Layer Dielectric (ILD) materials, therefore HAR vias are typically milled in dielectrics. Most of the etching precursor gases presently available for GAE of dielectrics on commercial FIB systems, such as XeF2, Cl2, etc., are also effective etch enhancers for either Si, or/and some of the metals used in ICs. Therefore use of these precursors for via milling in dielectrics may lead to unwanted side effects, especially in a backside circuit edit approach. Making contacts to the polysilicon lines with traditional GAE precursors could also be difficult, if not impossible. Some of these precursors have a tendency to produce isotropic vias, especially in Si. It has been proposed in the past to use fluorocarbon gases as precursors for the FIB milling of dielectrics. Preliminary experimental evaluation of Trifluoroacetic (Perfluoroacetic) Acid (TFA, CF3COOH) as a possible etching precursor for the HAR via milling in the application to FIB modification of ICs demonstrated that highly enhanced anisotropic milling of SiO2 in HAR vias is possible. A via with 9:1 aspect ratio was milled with accurate endpoint on Si and without apparent damage to the underlying Si substrate.

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