Characterization of Defects and Interfaces by the Ion Channeling Technique

1984 ◽  
Vol 41 ◽  
Author(s):  
W. K. Chu ◽  
S. T. Picraux
Keyword(s):  
Ion Beam ◽  
Strain Analysis ◽  
Crystal Defects ◽  
Interfacial Structure ◽  
Heteroepitaxial Growth ◽  
Ion Channeling ◽  
Light Ions ◽  
Recent Developments ◽  
Fast Light

AbstractChanneling of fast, light ions in crystals has been widely used as a tool for studying crystal defects. This subject has been reviewed earlier at MRS-1980. During MRS-1980, principles of ion channeling, and examples of channeling analysis on bulk defects and surface structures, lattice location of impurities, and clustering phenomena were given. In this review, we give a brief overview of defect studies by the channeling technique and then elaborate on recent developments in channeling analysis of interfacial structure. The ion beam channeling technique permits characterization of heteroepitaxial growth starting at monolayer coverages and allows quantitative measurement of the lattice strain in heteroepitaxial layers. The strain analysis has been developed for multilayer structures and, for example, the tetragonal distortions of strained-layer superlattices can be determined for lattice mismatches as low as 0.2% corresponding to lattice distortions of 0.01Å.

Electric Field Induced De-channeling in LiNbO3

1993 ◽  
Vol 316 ◽  
Author(s):  
R. L. Zimmerman ◽  
D. Ila ◽  
N. Kukhtarev ◽  
E. K. Williams
Keyword(s):  
Electric Field ◽  
Single Crystals ◽  
Ion Beam ◽  
Crystal Defects ◽  
Alpha Particles ◽  
Fringe Field ◽  
Beam Direction ◽  
Ion Channeling ◽  
Piezoelectric Strain ◽  
Mev Protons

ABSTRACTAn electric field has been imposed on single crystals of pure and doped LiNbO3 during bombardment with 1.03 MeV protons and 2.1 MeV alpha particles. Simultaneous (p,p), (p,α) and (p,p'γ) channeling between the crystal planes showed that the channeling is less pronounced when an electric field of 106 volts/m is imposed perpendicular to the incident ion beam direction and to the channeling planes in the crystal. The results obtained are discussed and compared to the effects due to the fringe field outside the crystal, differential cation-anion movement, movement of interplanar impurities, the piezoelectric strain and movement or creation of crystal defects on ion channeling.

Application of Channeling to Defect Studies in Crystals

1980 ◽  
Vol 2 ◽  
Author(s):  
W. K. Chu
Keyword(s):  
Defect Density ◽  
Bond Distance ◽  
Crystal Defects ◽  
Structural Defects ◽  
Substitutional Impurity ◽  
Structure Information ◽  
Surface And Interface ◽  
Impurity Atoms ◽  
Light Ions ◽  
Fast Light

ABSTRACTChanneling of fast, light ions in crystals has been widely used as a tool for studying crystal defects. Backscattering yield measurement on ions incident along major axial or planar crystalline directions provides information on the depth distribution of the structural defects in the first few microns. The channeling technique in defect detection is not as sensitive as Transmission Electron Spectroscopy, nor is it accurate in measuring the absolute numbers of defect density. Channeling measurements can give only an indication of the degree of lattice disorder. It is possible to distinguish one type of defect from another by carefully studying the energy dependence of the dechanneling. The dechanneling interpretation is not always unique, and in practice it is difficult to obtain structure information through that method. Despite these negative qualities, channeling is an attractive and unique method in certain defect studies. For example, it is sensitive for studying the lattice location of impurity atoms at substitutional or interstitial sites. Clustering of substitutional impurity atoms will show a displacement of the impurity atoms from lattice sites due to the change of bond distance. Channeling is sensitive for measuring impurity displacement as small as 0.1A°. This has been demonstrated in the study of arsenic clustering formation in Si. Interfacial relaxation and contraction in a multi-layered structure made by molecular beam epitaxy has been detected by dechanneling along various axial directions. Channeling study on surface and interface structures has developed over the past few years. In this paper, I will use examples to illustrate the unique features of the channeling technique and its application to defect studies in single crystals.

Defect studies in crystals by means of channeling

1968 ◽  
Vol 46 (6) ◽  
pp. 653-662 ◽  
Author(s):  
E. Bøgh
Keyword(s):  
Nuclear Reactions ◽  
Depth Resolution ◽  
Atomic Layer ◽  
Orientation Dependence ◽  
Crystal Defects ◽  
Structural Defects ◽  
Experimental Conditions ◽  
Light Ions ◽  
Set Up ◽  
Fast Light

Channeling of fast, light ions (e.g. protons and α particles) in crystals containing displaced atoms is discussed on the basis of Lindhard's theory, with the particular purpose of applying channeling as a tool for studying crystal defects. Measurements of the orientation dependence of the yield of close-encounter processes, such as nuclear reactions and wide-angle elastic scattering, can provide information about the depth distribution of structural defects in the first few microns beneath the surface of a single crystal. The relation between the yield and defect concentration is derived. This relation has led to a new double-alignment technique that combines channeling and blocking, and increases considerably the sensitivity for detecting structural defects.Scattering yield measurements in tungsten and silicon crystals covered with amorphous oxide layers of accurately known thickness are used to verify the results of the theoretical discussion. Double alignment is demonstrated. Criteria for selecting the optimal experimental conditions are set up. The sensitivity of the method for detecting lattice disorder corresponds to the displacement of ~1014–1015 atoms per cm2 (i.e. less than one atomic layer); the depth resolution with which, for example, radiation damage may be determined is ~50 Å.

Preparation and characterization of thin films of carbon nitride

1995 ◽  
Vol 53 ◽  
pp. 104-105
Author(s):  
L. Wan ◽  
R. F. Egerton
Keyword(s):  
Carbon Nitride ◽  
Arc Discharge ◽  
Ion Beam ◽  
Chemical Vapor ◽  
Reactive Sputtering ◽  
Vacuum Arc ◽  
Specimen Preparation ◽  
Bonding Structure ◽  
Electron Energy Loss

INTRODUCTION Recently, a new compound carbon nitride (CNx) has captured the attention of materials scientists, resulting from the prediction of a metastable crystal structure β-C3N4. Calculations showed that the mechanical properties of β-C3N4 are close to those of diamond. Various methods, including high pressure synthesis, ion beam deposition, chemical vapor deposition, plasma enhanced evaporation, and reactive sputtering, have been used in an attempt to make this compound. In this paper, we present the results of electron energy loss spectroscopy (EELS) analysis of composition and bonding structure of CNX films deposited by two different methods.SPECIMEN PREPARATION Specimens were prepared by arc-discharge evaporation and reactive sputtering. The apparatus for evaporation is similar to the traditional setup of vacuum arc-discharge evaporation, but working in a 0.05 torr ambient of nitrogen or ammonia. A bias was applied between the carbon source and the substrate in order to generate more ions and electrons and change their energy. During deposition, this bias causes a secondary discharge between the source and the substrate.

A TEM study of the interface between organic matrix and aragonite in a biological hard tissue, nacre

1992 ◽  
Vol 50 (2) ◽  
pp. 1024-1025
Author(s):  
Jun Liu ◽  
Katie E. Gunnison ◽  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Mechanical Properties ◽  
Ion Beam ◽  
Laminated Composite ◽  
Organic Matrix ◽  
Pearl Oyster ◽  
Interfacial Structure ◽  
Interfacial Region ◽  
Thin Sections ◽  
Organic Layers ◽  
Transmission Electron

The interfacial structure between the organic and inorganic phases in biological hard tissues plays an important role in controlling the growth and the mechanical properties of these materials. The objective of this work was to investigate these interfaces in nacre by transmission electron microscopy. The nacreous section of several different seashells -- abalone, pearl oyster, and nautilus -- were studied. Nacre is a laminated composite material consisting of CaCO3 platelets (constituting > 90 vol.% of the overall composite) separated by a thin organic matrix. Nacre is of interest to biomimetics because of its highly ordered structure and a good combination of mechanical properties. In this study, electron transparent thin sections were prepared by a low-temperature ion-beam milling procedure and by ultramicrotomy. To reveal structures in the organic layers as well as in the interfacial region, samples were further subjected to chemical fixation and labeling, or chemical etching. All experiments were performed with a Philips 430T TEM/STEM at 300 keV with a liquid Nitrogen sample holder.

Electron microscopic characterization of diamond thin films and substrates for diamond heteroepitaxial growth

1989 ◽  
Vol 47 ◽  
pp. 592-593
Author(s):  
J.B. Posthill ◽  
R.P. Burns ◽  
R.A. Rudder ◽  
Y.H. Lee ◽  
R.J. Markunas ◽  
...  
Keyword(s):  
Thin Films ◽  
Wide Band ◽  
Deposition Process ◽  
Heteroepitaxial Growth ◽  
Electron Microscopic ◽  
Wide Band Gap ◽  
Lattice Matching ◽  
Different Types ◽  
Diamond Thin Films

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.

HRTEM simulation of interfacial structure in amorphous multilayers

1989 ◽  
Vol 47 ◽  
pp. 466-467
Author(s):  
Margaret L. Sattler ◽  
Michael A. O'Keefe
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Cross Section ◽  
High Resolution Electron Microscopy ◽  
Interfacial Structure ◽  
Multilayer Sample ◽  
Resolution Electron ◽  
Multilayered Materials ◽  
Simulated Images

Multilayered materials have been fabricated with such high perfection that individual layers having two atoms deep are possible. Characterization of the interfaces between these multilayers is achieved by high resolution electron microscopy and Figure 1a shows the cross-section of one type of multilayer. The production of such an image with atomically smooth interfaces depends upon certain factors which are not always reliable. For example, diffusion at the interface may produce complex interlayers which are important to the properties of the multilayers but which are difficult to observe. Similarly, anomalous conditions of imaging or of fabrication may occur which produce images having similar traits as the diffusion case above, e.g., imaging on a tilted/bent multilayer sample (Figure 1b) or deposition upon an unaligned substrate (Figure 1c). It is the purpose of this study to simulate the image of the perfect multilayer interface and to compare with simulated images having these anomalies.

Shot-noise simulations of HREM images of polymer crystals

1989 ◽  
Vol 47 ◽  
pp. 342-343
Author(s):  
Philippe Pradère ◽  
Edwin L. Thomas
Keyword(s):  
Low Dose ◽  
Molecular Level ◽  
High Resolution Electron Microscopy ◽  
Crystal Defects ◽  
Inorganic Materials ◽  
Photographic Emulsion ◽  
Polymer Crystals ◽  
Resolution Electron ◽  
Recent Developments ◽  
Lattice Images

High Resolution Electron Microscopy (HREM) is a very powerful technique for the study of crystal defects at the molecular level. Unfortunately polymer crystals are beam sensitive and are destroyed almost instantly under the typical HREM imaging conditions used for inorganic materials. Recent developments of low dose imaging at low magnification have nevertheless permitted the attainment of lattice images of very radiation sensitive polymers such as poly-4-methylpentene-1 and enabled molecular level studies of crystal defects in somewhat more resistant ones such as polyparaxylylene (PPX) [2].With low dose conditions the images obtained are very noisy. Noise arises from the support film, photographic emulsion granularity and in particular, the statistical distribution of electrons at the typical doses of only few electrons per unit resolution area. Figure 1 shows the shapes of electron distribution, according to the Poisson formula :

Electrical Characterization of Different Failure Modes in Sub-100 nm Devices Using Nanoprobing Technique

2009 ◽  
Author(s):  
E. Hendarto ◽  
S.L. Toh ◽  
J. Sudijono ◽  
P.K. Tan ◽  
H. Tan ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Focused Ion Beam ◽  
Failure Modes ◽  
Ion Beam ◽  
Electrical Characterization ◽  
Nickel Silicide ◽  
Fault Isolation ◽  
Technology Nodes ◽  
Scanning Electron

Abstract The scanning electron microscope (SEM) based nanoprobing technique has established itself as an indispensable failure analysis (FA) technique as technology nodes continue to shrink according to Moore's Law. Although it has its share of disadvantages, SEM-based nanoprobing is often preferred because of its advantages over other FA techniques such as focused ion beam in fault isolation. This paper presents the effectiveness of the nanoprobing technique in isolating nanoscale defects in three different cases in sub-100 nm devices: soft-fail defect caused by asymmetrical nickel silicide (NiSi) formation, hard-fail defect caused by abnormal NiSi formation leading to contact-poly short, and isolation of resistive contact in a large electrical test structure. Results suggest that the SEM based nanoprobing technique is particularly useful in identifying causes of soft-fails and plays a very important role in investigating the cause of hard-fails and improving device yield.

Physical Failure Analysis Techniques for Front-End-of-Line Defect Analysis

2016 ◽  
Author(s):  
Dirk Doyle ◽  
Lawrence Benedict ◽  
Fritz Christian Awitan
Keyword(s):  
Cross Section ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Gate Oxide ◽  
Top Down ◽  
New Techniques ◽  
First Case ◽  
Transmission Electron ◽  
Scanning Transmission

Abstract Novel techniques to expose substrate-level defects are presented in this paper. New techniques such as inter-layer dielectric (ILD) thinning, high keV imaging, and XeF2 poly etch overflow are introduced. We describe these techniques as applied to two different defects types at FEOL. In the first case, by using ILD thinning and high keV imaging, coupled with focused ion beam (FIB) cross section and scanning transmission electron microscopy (STEM,) we were able to judge where to sample for TEM from a top down perspective while simultaneously providing the top down images giving both perspectives on the same sample. In the second case we show retention of the poly Si short after removal of CoSi2 formation on poly. Removal of the CoSi2 exposes the poly Si such that we can utilize XeF2 to remove poly without damaging gate oxide to reveal pinhole defects in the gate oxide. Overall, using these techniques have led to 1) increased chances of successfully finding the defects, 2) better characterization of the defects by having a planar view perspective and 3) reduced time in localizing defects compared to performing cross section alone.

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