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The behavior of laminated composite skew plates under different temperature variations is an important phenomena which was explored in this study. For modelling of laminated composite skew plate the suitable parabolic variation of transverse shear variation was considered. The skew effect was incorporated with transformation matrix detailed in the manuscript. Due to parabolic variation of transverse shear considered the need of shear correction factor was circumvented in present work. The different type of temperature variations were considered in the present work. The parametric variations of skew angle, plate thickness etc. were varied to study the temperature variation behavior on laminated composite skew plate. The authors developed the FORTRAN code for the finite element formulation of present mathematical model along with temperature variations incorporations. Nine node isoparametric finite elements were used in the present FE formulation. Top and bottom zero transverse shear stresses were implied in present formulations to calculate unknown parameters. The developed model 2D allowed prediction of results close to 3D solution. The presented method work results are in close resemblance with previously published results obtained by other methods.

The CPVA (Cantilever Piezoelectric Vibration Absorber) is a mechanism that combines working principles of DVA and energy harvesting to reduce vibration while generating voltage. The system’s response that need to be reduced by the CPVA is a plat as a primary mass which has 3 degree-of-freedom those are translation, rolling, and pitching vibration direction. The optimum configuration of this mechanism has the objective in order to reach a maximum percentage of reduction while generating voltage. The variation of piezoelectric’s amount and several nodes position where its mechanism is installed on the primary system need to be optimally selected to implement satisfactory performance. Simulation provides valuable insights in dynamical characteristics in each nodes and results the optimum value of the reduction and voltage generation in the 8th node position with the amount of 100 pieces of piezoelectric, which succeed for reducing translational, rolling, and pitching direction up to 79.8%; 76.1%; and 79.69% respectively.The CPVA (Cantilever Piezoelectric Vibration Absorber) is a mechanism that combines working principles of DVA and energy harvesting to reduce vibration while generating voltage. The system’s response that need to be reduced by the CPVA is a plat as a primary mass which has 3 degree-of-freedom those are translation, rolling, and pitching vibration direction. The optimum configuration of this mechanism has the objective in order to reach a maximum percentage of reduction while generating voltage. The variation of piezoelectric’s amount and several nodes position where its mechanism is installed on the primary system need to be optimally selected to implement satisfactory performance. Simulation provides valuable insights in dynamical characteristics in each nodes and results the optimum value of the reduction and voltage generation in the 8th node position with the amount of 100 pieces of piezoelectric, which succeed for reducing translational, rolling, and pitching direction up to 79.8%; 76.1%; and 79.69% ...

The application of laminated sandwich composite in machine structures is attractive due to the low specific and tailorable properties of the composites. As such a study on the parametric instability that often occurs in machine structures should be crucially conducted on composite plates. In this paper, finite element method (FEM) has been used to model laminated composite plate subjected to periodic compressive loading for the parametric instability analysis. The FEM formulation is based on the first order shear deformation theory. Eight noded serendipity element that requires 5 degrees of freedom per node is used in this study. The developed Mathieu-Hill type equation that represents the parametric instability of the composite plate has been solved using the Bolotin’s method that reduces the Mathieu-Hill equation to a couple of eigen-value problems. The FEM source codes have been developed to determine the instability charts for several configurations of composite plates. While the formulation and codes...

Construction of nodal and element-wise linear (known as P1) gradient field from element-wise constant (known as P0) gradient field obtained by the P1 finite element methods on defined triangular mesh is based on works of J. Dalik et al. and it is briefly explained and numerically tested in this contribution. Nodal value of P1 gradient is computed by averaging of P0 gradients on elements sharing the node in a common patch.

In this work particle image velocimetry (PIV) was employed to probe the motion of particles within a quasi-2D vibrated bed of circular cross-section. We have observed a polygon-shaped pattern for Γ = A(2π f)2/g greater than 10. It has been argued that the polygon pattern formed in 2D cylindrical beds is related to the arching structure encountered in squareshaped vibrated beds [G. Lu, J. R. Third, M. H. Kohl, and C. R. Muller, 2012. On the occurrence of polygon-shaped patterns in vibrated cylindrical granular beds. The European Physical Journal E 35, 90.]. However, using PIV a significant difference in the velocity profiles in the polygon and the arching patterns was observed. We found that in the arching structure the velocity profile around a node was highly symmetric, whereas this was not the case for the polygon structure. Using cylindrical beds of different diameters filled with a constant number of particles, we could confirm that the spatially varying filling height of cylindrical beds is the main ...

Directed self‐assembly (DSA) of block copolymers (BCPs) is a technology that combines lithographically defined physical or chemical features to guide self‐assembled polymers to create features smaller than those possible with conventional lithography. To the semiconductor industry DSA represents a possible lithography solution below 22–16 nm node where the targeted line edge roughness (LER) is 1.4 nm or less. This LER requirement presents a challenge for DSA to become a viable lithography solution. Hitherto the LER of DSA block copolymers was measured mostly using SEM and AFM, hence the results represent only the top surface characteristics. In addition, the observed LER using SEM or AFM is often greater than 1.3 nm. The purpose of this work is to demonstrate the use of transmission X‐ray scattering to quantify LER as well as the critical dimensions in BCP patterns created with the DSA technique. Experimental results from poly(styrene‐b‐methyl methacrylate) copolymer line gratings with 23 nm half pitch will be presented and the theoretical developments needed to extract LER from X‐ray scattering will also be discussed.

Frequency loci crossing and veering phenomena are closely related to wave propagation and instabilities in fluids and structures. In engineering applications the crossings of the eigencurves are typically observed in gyroscopic or potential systems in the presence of symmetries, such as rotational or spherical one. The examples are perfect solids of revolution that serve for modeling turbine wheels, disk and drum brakes, tires, clutches, paper calenders and other rotating machinery. We consider an axi‐symmetric flexible rotor perturbed by dissipative, conservative, and non‐conservative positional forces originated at the contact with the anisotropic stator. The Campbell diagram of the unperturbed system is a mesh‐like structure in the frequency‐speed plane with double eigenfrequencies at the nodes. Computing sensitivities of the doublets we find that at every particular node the unfolding of the mesh into the branches of complex eigenvalues in the first approximation is generically determined by only four...

45 nm‐node Cu interconnects with air gaps were studied to confirm the feasibility to the next node (32 nm) and beyond. The air‐gap formation technology that we proposed was characterized by “air‐gap exclusion” (AGE), which selectively excluded the air gaps from undesired regions such as wide spaces between lines and peripheries of vias. A high‐Young’s‐modulus SiOC (HM‐SiOC) with k value of 3.0 was used to form the air gaps. However, effective dielectric constant (Keff) as low as 2.3, which surpassed ITRS requirement for hp45 by far, was obtained. Mechanical characteristics of the Cu interconnects structure with the air gaps were studied systematically. Effective Young’s elastic modulus was measured by a nano‐indention method. The measurements show that it changes little with air‐gap density. A nano‐scratch test revealed that dominant fracture mode of the Cu interconnects structure with air gaps was not collapse of the air gaps but delaminations between the dielectrics. In addition, above phenomena are explained and supported by finite‐element‐analysis (FEA) stress‐simulations. As a result, it was confirmed that the air‐gap formation does not degrade mechanical characteristics of the Cu interconnects structure with air gaps. In contrast to low‐k based technology, this air‐gap formation technology is very promising for the next node (32 nm) and beyond because it can reduce Keff significantly while keeping the mechanical strength of Cu interconnects structure high.

We investigate the vibrations of the ideal flexible string, which one end is rigidly clamped, or coupled with a linear damped oscillator, and another one is terminated on the curved contact surface. The vibrating string touches repeatedly this termination, and this, in turn, causes the modulation of fundamental frequency of the string, and the train of high frequency oscillations is generated. The problem is studied both analytically, and numerically. The effect of the contact nonlinearity and of the shape of the contact surface on of the spectral structure of the string vibration is considered. The influence of the impact amplitude on the vibration spectra of struck string is discussed.

As the industry moves to the new technology nodes of 45 nm and 32 nm devices, implant angle control becomes even more crucial for consistent device performance. Commercial single wafer ion implanters are able to measure and correct the horizontal incident angle of the ion beam. But the vertical beam angle (VBA) control has become a very important parameter as well. In this work the authors demonstrate the impact of a tilt variation for a 65 nm and a 45 nm MOS transistor generated by different beam setups on one machine. Comparisons are made for each technology with a controlled angle variation of ±4°. The Vt‐distribution should be reduced with better incident angle control allowing faster development of a new transistor node base line using the new VBA control technique from Axcelis.

The direct depth measurement of structures with aspect ratios between 1 and 4 in the arrays of memory cells represents a major challenge for inline metrology. For 75 nm and larger technology nodes these measurements are carried out using inline AFM using 50±5 nm diameter cylindrical AFM probes. However, for 58 nm and smaller technology nodes these AFM probes are not capable anymore, because the tip diameter is comparable to the diameter of the trench structures themselves. Here we report about the development of 30 nm diameter cylindrical AFM probes suitable for direct depth measurements of 58 nm ground rule (GR) structures. The focus of the development was on tip lifetime, gage capability and throughput in a high volume environment. For the tests two different tip materials—silicon (Si) and electron beam deposited (EBD) carbon were investigated. Both tip types proved to be fully gage capable, and showed no throughput losses in comparison to larger node measurements. The tip lifetime under production cond...

The observation of parasitic low‐VSWR activity during operations of JET RF plant and the damage caused by arcing at the voltage‐node in the vacuum transmission line (VTL) in 2004 highlight the importance of the problem of low‐voltage breakdown in the ICRH systems. Simulations demonstrate little response of the RF circuit to the voltage‐node arcing which explains why it remains largely unnoticed and complicates the design of protection systems. Analysis of the damage pattern produced by the voltage‐node arcing suggests that multipactor‐related phenomena occurring at elevated voltage thresholds in conditions of unfavorable VTL geometry are most plausible arc‐provoking factors.

The automated metrology tool, combining X‐ray reflectivity XRR and small‐angle X‐ray scattering SAXS has been demonstrated as a capable equipment to assess standard porous Ultra low‐κ (ULK) metrology. Therefore those techniques have enabled characterizations of several ULK used in sub‐65 nm nodes integration. Standard ULK material for 65 nm node technology has been monitored through the whole C065 integration steps using those combined techniques.

The radial and translational motion of small gas bubbles in the near field region of a pulsating piston and in a plane propagation sound wave was studied experimentally and by numerical simulations. It was established that the sub‐resonance size gas bubbles move toward the axis of symmetry of the piston‐zone of the pressure antinodes. As a result of convective diffusion and coagulation, those small bubbles, the nucleus of cavitation, grow in size. The special role of the rigid surface of the piston in keeping the bubbles near the surface is noted. It is established that while moving toward the node of pressure, the amplitude of the bubble pulsation increases, and nonlinearity results in typical cavitation noise on the sub‐harmonics of the main frequency. A series of cavitation impulses is noted. The fact that gas bubbles eject at a high speed from the zone of the antinodes of pressure away of the piston surface is established both by numerical simulations and experiments. Growth in size and the fact that the resonance radius depends on the amplitude both contribute to this ejection. Some generalization about the behavior of trans‐resonant bubbles in different inhomogeneous sound fields is made.

With the rapid acceptance of single wafer high current implanters for 90nm technology node and beyond, the challenge that customers face is to device match the single wafer system to their existing batch production line. Due to the differences in scanning architecture, the damage rates will differ significantly between tools and thus can cause variations in amorphous layer thickness and residual defects which impact the post anneal junction depth and activation level. In this study we investigate the damage differences between single wafer and batch implanters for Germanium pre‐amorphising implants over a range of energies. Implants were performed on an Applied Quantum® X single wafer implanter and a Quantum® III batch implanter. Amorphous layer thickness was measured using TEM and activation was monitored using sheet resistance.

Implant angle control is increasingly important with each new device node. Some devices have demonstrated a sensitivity of threshold voltage of about 100 mV/deg for implant angle and require implant angles to be held within +/− 0.2° for process control. There are many sources of angle variation in single wafer implanters. Mechanical orientation can usually be controlled to high precision, but an accurate control of the implant angle requires knowledge of the actual beam angle relative to the surface or crystal planes of the wafer. In‐situ methods to measure beam angles in both the horizontal and vertical planes are required and it is necessary that these methods be calibrated to the surface or crystal planes of the wafer to achieve the required angle control. Optima MD has incorporated methods to automatically measure beam angles prior to implant in both planes, and correct for any deviation from the desired implant angle. The symmetric parallelizing lens that corrects angles without bending the beam enables a method of calibrating the horizontal angle mask to crystal planes with one or two wafers. This paper discusses the methods of measurement, calibration, and accuracy of the Optima MD angle control system.

An impedance irregular network is proposed to investigate electrical fluctuations of biomolecules anchored between Ohmic contacts. We take rhodopsin as prototype of a biomelecule and as source of fluctuations we consider the random oscillations of the distances between aminoacids (link oscillation model) or alternatively those of the position of the aminoacids around their static value (node oscillation model). The network impedance and its variance are then investigated as function of the amplitude of the fluctuations. Analogies and differences between the results of the two models are discussed and some open problems are identified.

A Finite Element code is used in a stationary mode to compute, at single a frequency, the stress and displacement fields in a plate made of anisotropic viscoelastic materials. An appropriated spatial load at one boundary of the plate is applied to generate a guided Lamb wave mode. The number of frequency iterations (≈ usually less than 30) is limited by the frequency content of the excitation. Then, the temporal response at any node of the plate can be reconstructed with inverse FFT. The velocity, attenuation and nature of one or several propagating modes can be identified in the classical frequency/wave number representation. This paper shows the effect of the attenuation on the propagation of Lamb waves in a cross‐ply, carbon‐epoxy material plate. Focus is made on some limitations that the attenuation causes on the detection of a delamination between plies.

The results on the measurement of the analyzing power component T20 in elastic ed scattering are presented. An internal storage cell target technique was used in the VEPP-3 electron ring in Novosibirsk for this measurement. The measurement has been performed in the range of momentum transfer poorly investigated but important from theoretical point of view because of the node of the monopole charge form factor of the deuteron. The comparison of the other experimental data and some theories are discussed.

This paper deals with an experimental set-up to study finite amplitude standing waves in an axi-symmetrical chamber with transversal dimension longer than the wavelength. The cavity is driven by means of a high-power transducer flexurally vibrating which allows to have high pressure values in the cavity. The transducer, working at a fixed frequency, is a very efficient system with a high Q-value. In order to tune the different resonant modes, the wall in front of the transducer can be moved parallel to the axis of the chamber. Measurements of the fundamental and second order components of the acoustic field have been made on the axis of the chamber. Attenuation has been evaluated for every resonant length and harmonic component.

It is shown that optical elements placed at interference minima of a radiation field will damage less. For example, when a 103⋅ A (or 3.15⋅103 A) thick metallic foil is placed at the node of a standing wave pattern produced by 30 μm wavelength radiation polarized parallel to the foil surface, the damage due to Joule heating is calculated to decrease by a factor 6.8⋅103 (6.8⋅104). When the angle of incidence is θ=5.7⋅ and the wave is polarized parallel to the plane of incidence, the factor is 5.8⋅102 (1.8°103). Thus, higher fields are possible near mirrors, without damage. Applying this phenomenon to laser template accelerator design allows ≊ 1GeV/m acceleration at any (including very high) particle energy. Experiments could determine how much of the calculated increase can be realized and where and if other damage mechanisms may take over.