scholarly journals Microtexture and Strain in Electroplated Copper Interconnects

2000 ◽  
Vol 612 ◽  
Author(s):  
R. Spolenak ◽  
D. L. Barr ◽  
M. E. Gross ◽  
K. Evans-Lutterodt ◽  
W. L. Brown ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Local Strain ◽  
Spot Size ◽  
Electron Back Scatter Diffraction ◽  
Grain Structure ◽  
X Rays ◽  
Area Detector ◽  
Submicron Scale ◽  
Electroplated Copper

AbstractThe microstructure of narrow metal conductors in the electrical interconnections on IC chips has often been identified as of major importance in the reliability of these devices. The stresses and stress gradients that develop in the conductors as a result of thermal expansion differences in the materials and of electromigration at high current densities are believed to be strongly dependent on the details of the grain structure. The present work discusses new techniques based on microbeam x-ray diffraction (MBXRD) that have enabled measurement not only of the microstructure of totally encapsulated conductors but also of the local stresses in them on a micron and submicron scale. White x-rays from the Advanced Light Source were focused to a micron spot size by Kirkpatrick-Baez mirrors. The sample was stepped under the micro-beam and Laue images obtained at each sample location using a CCD area detector. Microstructure and local strain were deduced from these images. Cu lines with widths ranging from 0.8 [.proportional]m to 5 [.proportional]m and thickness of 1 [.proportional]m were investigated. Comparisons are made between the capabilities of MBXRD and the well established techniques of broad beam XRD, electron back scatter diffraction (EBSD) and focused ion beam imagining (FIB).

Mechanical Properties of Electroplated Copper Thin Films

1999 ◽  
Vol 594 ◽  
Author(s):  
R. Spolenak ◽  
C. A. Volkert ◽  
K. Takahashi ◽  
S. Fiorillo ◽  
J. Miner ◽  
...  
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Grain Size ◽  
Film Thickness ◽  
Yield Stress ◽  
Laser Scanning ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Cu Films ◽  
Electroplated Copper

AbstractIt is well known that the mechanical properties of thin films depend critically on film thickness However, the contributions from film thickness and grain size are difficult to separate, because they typically scale with each other. In one study by Venkatraman and Bravman, Al films, which were thinned using anodic oxidation to reduce film thickness without changing grain size, showed a clear increase in yield stress with decreasing film thickness.We have performed a similar study on both electroplated and sputtered Cu films by using chemical-mechanical polishing (CMP) to reduce the film thickness without changing the grain size. Stress-temperature curves were measured for both the electroplated and sputtered Cu films with thicknesses between 0.1 and 1.8 microns using a laser scanning wafer curvature technique. The yield stress at room temperature was found to increase with decreasing film thickness for both sets of samples. The sputtered films, however, showed higher yield stresses in comparison to the electroplated films. Most of these differences can be attributed to the different microstructures of the films, which were determined by focused ion beam (FIB) microscopy and x-ray diffraction.

PLANAR JOSEPHSON JUNCTIONS FABRICATED BY FOCUSED-ION BEAM

2001 ◽  
Vol 15 (24n25) ◽  
pp. 3359-3360 ◽  
Author(s):  
Hye-Won Seo ◽  
Quark Y. Chen ◽  
Chong Wang ◽  
Wei-Kan Chu ◽  
T. M. Chuang ◽  
...  
Keyword(s):  
Silicon Dioxide ◽  
Josephson Junctions ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Spot Size ◽  
Physical Significance ◽  
Fabrication Technique ◽  
Beam Spot ◽  
Beam Spot Size ◽  
Current Voltage

We have fabricated nano-scaled planar superconductor-insulator-superconductor Josephson junctions using focused ion beam (FIB) with beam spot size ~5 nm . To study the effectiveness of this fabrication technique and for the purpose of comparisons, a variety of samples have been made based on high temperature superconducting (HTS) YBa2Cu3O7-δ electrodes. The insulators are either vacuum or silicon dioxide. The samples showed current-voltage (IV) characteristics typical of a resistively shunted junction (RSJ). We will discuss various aspects of the processing methods and the physical significance of the junction characteristics.

A Compact Nuclear Microprobe With a Liquid Metal Ion Source and a Toroidal Analyzer

1992 ◽  
Vol 295 ◽  
Author(s):  
Mikio Takai ◽  
Ryou Mimura ◽  
Hiroshi Sawaragi ◽  
Ryuso Aihara
Keyword(s):  
Liquid Metal ◽  
Metal Ion ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
High Vacuum ◽  
Spot Size ◽  
Ion Source ◽  
Ultra High Vacuum ◽  
Atomic Resolution ◽  
Nuclear Microprobe

AbstractA nondestructive three-dimensional RBS/channeling analysis system with an atomic resolution has been designed and is being constructed in Osaka University for analysis of nanostructured surfaces and interfaces. An ultra high-vacuum sample-chamber with a threeaxis goniometer and a toroidal electrostatic analyzer for medium energy ion scattering (MEIS) was combined with a short acceleration column for a focused ion beam. A liquid metal ion source (LMIS) for light metal ions such as Li+ or Be+ was mounted on the short column.A minimum beam spot-size of about 10 nm with a current of 10 pA is estimated by optical property calculation for 200 keV Li+ LMIS. An energy resolution of 4 × 10-3 (AE/E) for the toroidal analyzer gives rise to atomic resolution in RBS spectra for Si and GaAs. This system seems feasible for atomic level analysis of localized crystalline/disorder structures and surfaces.

Focused Ion Beam Nano-Machined Structures For Strain Analysis By A Moiré Technique

2002 ◽  
Vol 761 ◽  
Author(s):  
Biao Li ◽  
Huimin Xie ◽  
Xin Zhang
Keyword(s):  
Focused Ion Beam ◽  
Microelectromechanical Systems ◽  
Ion Beam ◽  
Accurate Determination ◽  
Strain Analysis ◽  
Local Strain ◽  
Ion Milling ◽  
Nano Fabrication ◽  
In Situ Deposition ◽  
Potential Applications

ABSTRACTThe accurate determination of residual stress/strain in thin films is especially important in the emerging field of MicroElectroMechanical Systems (MEMS). In this article, a focused ion beam (FIB) moiré method is proposed and demonstrated to measure the strain in MEMS structures. This technique is based on the advantages of the FIB system in nano-fabrication, imaging, in-situ deposition, and fine adjustment. Nano-grating lines with 70 nm width and 140 nm spacing are directly written on the top of the MEMS structures by ion milling without the requirement of an etch mask. The FIB moiré pattern is formed by the interference between a prepared specimen grating and FIB raster scan lines. The strain of the MEMS structures is derived by calculating the average spacing of moiré fringes. Since the local strain of a MEMS structure itself can be monitored during the process, the FIB moiré technique has many potential applications in the mechanical metrology of MEMS. As an example, the strain distribution along the sticking MEMS structures, and the contribution of surface oxidization and mass loading to the cantilever strain is determined by this FIB moiré technique.

A New Technique For Visualizing The Displacement Field Of Indentations: The Case Of A Soft Film On A Hard Substrate

1997 ◽  
Vol 505 ◽  
Author(s):  
Joost J. Vlassak ◽  
T. Y. Tsui ◽  
W. D. Nix
Keyword(s):  
Titanium Nitride ◽  
Displacement Field ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Grain Structure ◽  
New Technique ◽  
Hard Substrate ◽  
Film Material ◽  
Pile Up ◽  
A New Technique

ABSTRACTWe have developed a new technique for visualizing displacement fields of indentations in thin films. In this technique, the indented film consists of alternating layers of two different materials. One of the materials serves as a marker for visualizing the plastic flow induced by the indentation. Focused Ion Beam (FIB) milling is used to cross-section the indentation, revealing the deformed layers. This technique can be used to study how the presence of the substrate affects the plastic displacement field around the indentation. The technique is applied to a multilayered film of aluminum and titanium nitride on a silicon substrate. The titanium nitride layers are much thinner than the aluminum layers and serve the function of marker. Pile-up of the film material around the indenter and the effect of the hard substrate are easily revealed and a mechanism for pile-up is suggested. The technique also shows that the grain structure in the deformed zone around the indentation is altered profoundly.

Characterization of Plated Cu Thin Film Microstructures

1999 ◽  
Vol 564 ◽  
Author(s):  
L. M. Gignac ◽  
K. P. Rodbel ◽  
C. Cabral ◽  
P. C. Andricacos ◽  
P. M. Rice ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Grain Structure ◽  
Grain Structures ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Gaussian Fit ◽  
Cu Thin Film ◽  
Log Normal ◽  
Electron Imaging

AbstractElectroplated Cu was found to have a fine as-plated microstructure, 0.05 ± 0.03 μm, with multiple grains through the film thickness and evidence of twins and dislocations within grains. Over time at room temperature, the grains grew to greater than 1 μm in size. Studied as a function of annealing temperature, the recrystallized grains were shown to be 1.6 ± 1.0 μm in size, columnar and highly twinned. The grain growth was directly related to the time dependent decrease in sheet resistance. The initial grain structure was characterized using scanning transmission electron microscopy (STEM) from a cross-section sample prepared by a novel focused ion beam (FIB) and lift-out technique. The recrystallized grain structures were imaged using FIB secondary electron imaging. From these micrographs, the grain boundary structures were traced, and an image analysis program was used to measure the grain areas. A Gaussian fit of the log-normal distribution of grain areas was used to calculate the mean area and standard deviation. These values were converted to grain size diameters by assuming a circular grain geometry.

scholarly journals Polymer micro-lenses as an long-coupling-distance interfacing layer in low-cost optical coupling solution between optical fibers and photonic integrated waveguide circuits

2019 ◽  
Vol 11 (4) ◽  
pp. 121
Author(s):  
Andrzej Kaźmierczak ◽  
Mateusz Słowikowski ◽  
Krystian Pavłov ◽  
Maciej Filipiak ◽  
Ryszard Piramidowicz
Keyword(s):  
Optical Fiber ◽  
Focused Ion Beam ◽  
Low Cost ◽  
Ion Beam ◽  
Single Mode ◽  
Optical Fiber Communication ◽  
Japanese Journal ◽  
Spot Size ◽  
Optical Signal ◽  
Silicon On Insulator

We present a low-cost scheme for non-permanent optical signal coupling for prospective application in single use photonic integrated chips. The proposed scheme exploits the use of polymer kinoform microlenses. The feasibility of the proposed solution is demonstrated by the experimental investigation of the optical signal coupling from single mode optical fiber (SMF) to the test structure of SixNy integrated waveguide. Full Text: PDF ReferencesM. Smit et al., "An introduction to InP-based generic integration technology," Semiconductor Science and Technology, 29 (8), 083001, 2014 CrossRef R. Baets et al., "Silicon Photonics: silicon nitride versus silicon-on-insulator," in Optical Fiber Communication Conference, OSA Technical Digest (online) (Optical Society of America, 2016), paper Th3J.1. CrossRef K. Shiraishi et al., "A silicon-based spot-size converter between single-mode fibers and Si-wire waveguides using cascaded tapers," Appl. Phys. Lett. 91, 141120 (2007) CrossRef Y. Sobu et al., "GaInAsP/InP waveguide dual core spot size converter for optical fiber,"IEEE Photonic Society 24th Annual Meeting, 469-470, (2011). CrossRef F. Van Laere et al., "Compact and Highly Efficient Grating Couplers Between Optical Fiber and Nanophotonic Waveguides," Journal of Lightwave Technology, vol. 25, no. 1, pp. 151-156, Jan. 2007. CrossRef A. Kaźmierczak et al., "Light coupling and distribution or Si3N4/SiO2 integrated multichannel single mode sensing system," Opt. Eng. 48, 2009, pp. 014401 CrossRef M. Rossi et al., "Arrays of anamorphic phase-matched Fresnel elements for diode-to-fiber coupling," Appl. Opt. 34, 2483-2488 (1995) CrossRef M. Prasciolu et al, "Fabrication of Diffractive Optical Elements On-Fiber for Photonic Applications by Nanolitography," Japanese Journal of Applied Physics, Volume 42, (2003) CrossRef F.Schiappelli et al., "Efficient fiber-to-waveguide coupling by a lens on the end of the optical fiber fabricated by focused ion beam milling" Microelectronic Engineering Volumes 73-74, pp.397-404 (2004) CrossRef

The Challenges of FIB Chip Repair and Debug Assistance in the 0.25μm Copper Interconnect Millennium

1998 ◽  
Author(s):  
S.B. Herschbein ◽  
L.S. Fischer ◽  
T.L. Kane ◽  
M.P. Tenney ◽  
A.D. Shore
Keyword(s):  
High Performance ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Grain Structure ◽  
Long Term Storage ◽  
Wagon Wheel ◽  
Sram Cell ◽  
Oxide Deposition ◽  
Reliable Isolation

Abstract Copper will probably replace aluminum alloys as the interconnect metallurgy of choice for high performance semiconductor devices. This transition will challenge the suitability of established practices in focused ion beam (FIB) chip repair. A fundamental rethink in methodology, techniques, and process gases will be required to deal with the new metal films. This paper discusses the results of recent experiments in the areas of FIB exposure, cuts and connections to buried copper lines. While copper tends to mill faster than aluminum, etch rate variations due to grain structure tend to make reliable isolation cuts more difficult. The films also have been shown to suffer regrowth and surface reactions during long term storage following FIB exposure. Attempts at halogen gas assisted etch (GAE) mills result in undesirable removal characteristics, and in the case of bromine, the spontaneous destruction of all exposed copper in the immediate area. Resistance measurements and reliability of deposited tungsten connections to copper lines are also presented. In addition, the latest techniques developed for aluminum wiring isolation and device characterization are shown. These include 'cleanup' methods for achieving good circuit isolation without the extensive use of local oxide deposition, and the latest multilevel version of the FIB ‘wagon wheel’ for SRAM cell characterization. Also included is preliminary data from a custom built FIB chamber four manipulator prober module.

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