摘要:

AbstractWith a view to application to millimeter wave integrated circuits, we analyze theoretically resonance characteristics of a whispering gallery mode (W.G. mode) propagating along a circumference of an elliptical dielectric cylinder. A wave equation is derived in an elliptic coordinate system and an eigenvalue equation includes Mathieu functions with a large order is obtained. Since this eigenvalue equation is an infinite dimensional determinant, we introduce a new technique to solve the eigenvalue equation. In this determinant, we pay our attention to diagonal elements that affect mainly resonance order. By means of this approach, it becomes possible to estimate a number of approximate terms of the eigenvalue equation to keep an accuracy of a resonance frequency constant even if an eccentricity of the ellipse is increased, namely the ellipse is flatter. It is also possible to find numerically the resonance frequency and electric field distribution of the W.G. mode for the elliptical cylinders with various eccentricity.

ISSN:8756-663X    

DOI:10.1002/ecjb.4420781201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractTo miniaturize the hybrid‐ring, a design method is presented herein for the circuit in which there is an electromagnetic coupling between the transmission lines in folded transmission lines. A 3‐dB branch‐line hybrid‐ring is treated. Analysis is carried out for the two cases of homogeneous and inhomogeneous circuit configurations in which each section has only one coupled line. It is found that in the circuit with a homogeneous configuration, perfect match and complete isolation hold at the center frequency as in the conventional type; additionally, the bandwidth becomes narrower as the coupling becomes stronger. In the inhomogeneous structure where the phase velocities of the even and odd modes are different, there is a shift in characteristics. An equal power division can still be accomplished if the degree of coupling and the phase shift in the coupled lines are appropriately chosen. The overall characteristics differ little from the conventional type. To confirm these findings, an inhomogeneous circuit is constructed and the results are found to agree with the

ISSN:8756-663X    

DOI:10.1002/ecjb.4420781202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractIn a nondispersive absorbing medium, a geometrical optics field using a complex eikonal is defined. The field is decomposed into two circular polarization components. If the circularly polarized electromagnetic energy fluxes are considered, it is shown that two rays can be defined for the right‐handed and left‐handed circularly polarized field, not in the sense of the energy flux (or the effective power flux), but of the absolute value of the energy flux (or the apparent power flux).This paper presents the basic relationships such as the relationship between the eikonal and the ray vectors and the propagation equations of the ray intensit

ISSN:8756-663X    

DOI:10.1002/ecjb.4420781203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractTo analyze the magnetization‐pattern relaxation by the nonlinear dynamical approach, an Ising model in the time‐dependent spin system (kinetic Ising model) is extended to a space‐dependent spin field. By solving the nonlinear diffusion equation on the spin order parameter derived by this formulation, the space‐time evolution of the magnetization pattern can be traced. Specifically, the fifth‐order Ginzburg‐Landau‐type equation in the null applied magnetic field is derived.Two kinds of nontrivial stationary solutions (lump and hole solutions) are presented. The spatial distributions of the stationary solutions are algebraic. Particularly, the lump solution is given as a square root of the Lorentz distribution. From the results of the numerical experiment, it is found that the lump solution is extremely unstable and decays very quickly whereas the hole solution is stable and is not subjected to relaxation. An approximate lump solution for many spatial dimensions is investi

ISSN:8756-663X    

DOI:10.1002/ecjb.4420781204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractA surface acoustic wave (SAW) electrostatic voltage sensor was fabricated using an SAW oscillator. In the electrostatic voltage sensor, the electrodes to apply electrostatic voltage and produce strain by piezoeffect are not located on the top and bottom surfaces of the substrate but rather on the propagation surface in parallel to the propagation path. Therefore, it is possible to reduce the gap spacing between the electrodes to apply an electrostatic voltage so that the sensitivity can be improved. When an electrostatic voltage is applied, the LiNbO3single crystal and PZT ceramic were used as substrates in this experiment. The most sensitive crystal plane in a rotatedY‐Xplate rotating about theXaxis was obtained for LiNbO3single crystal. It was found the result shows that the 90° rotationY‐Xplate is the best.In the experiment, a 131° rotationY‐Xplate with 20 × 25 × 1.0 mm3was used which is close to the derived angle and is obtained easily. The interdigital transducer (IDT) electrodes and the electrodes for applying electrostatic voltage were fabricated by Al evaporation. The characteristics of the oscillation frequency versus electrostatic voltage of the sensors were studied. The sensitivity was 0.133 Hz/V and 0.03 Hz/V for the 131° rotationY‐Xplate and aY‐Xplate in the case of LiNbO3. In the case of PZT ceramic, the sensitivity was 12 Hz/V. The dependence of the sensitivity on gap distance between the electrodes for applying electrostatic voltage and on temperature wa

ISSN:8756-663X    

DOI:10.1002/ecjb.4420781205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThe gap between patterned aluminum was filled with SiO2formed by the reaction of SiH4‐O2gas using helicon plasma and a biased substrate. The relationship between the SiO2deposition rate and plasma source power was investigated.It was found that the SiO2deposition rate was dependent on the rate of SiH4supply and was independent of the plasma source power. The sputtering rate due to biasing the substrate decreased with increase of the plasma source power. It was found also that the sputtering rate at which void generation is suppressed could be controlled not only by the bias power but also by the plasma source power. Even when the plasma source power and bias power were set at a low level, a sufficient sputtering rate was obtained. The gap‐filling rate (the net deposition rate) was determined by the difference between the raw deposition rate determined by SiH4supply and the sputtering rate and could be controlled by the plasma source po

ISSN:8756-663X    

DOI:10.1002/ecjb.4420781206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractIt is known that the reflectivity of aluminum (Al) film deposited by chemical vapor deposition (CVD) decreases with an increase of film thickness as its surface roughens. A thin, smooth film is effective for filling small holes and narrow trenches by confonmal deposition, but a rough surface is not effective.In this study, a real‐time monitoring of the CVD‐A1 film deposition process has been attempted by measuring the reflected light intensity at the depositing film surface. By finishing the deposition when the monitored reflected light intensity of the He‐Ne laser reached the maximum, a film with a very smooth surface could be reproduced. Furthermore, the lower limitation of smooth continuous film thickness was compared for four different cases.Investigated underlayers were Ti and TiN deposited by sputtering (SPT). On these underlayers, CVD‐Al film was deposited without exposure to atmosphere or with exposure to atmosphere prior to the deposition, resulting in a total of four deposition conditions. The results showed that Al film deposited on TiN without exposure to atmosphere had the thinnest and the smoothest continuous film among the four. Since the thickness was 60 nm, the filling of 0.12‐μm diameter holes or 0.12‐μm wide trenches can be expected by

ISSN:8756-663X    

DOI:10.1002/ecjb.4420781207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractFormation of a TiN/Ti adhesion layer by collimated sputtering for a structured surface with a high aspect ratio was investigated. The bottom coverage was simulated and the simulated and experimental results were compared. As a result, it was found that the simulated and experimental results were in agreement if the scattering of sputtered particles by gas was small.Three‐dimensional simulation of wall coverage predicted a formation of constriction at the top of the contact hole and the formation of constriction was confirmed experimentally. The formation of constriction caused the peeling of an adhesion layer when a chemical vapor deposition (CVD) tungsten film was deposited. To avoid the formation of constriction, a tapered contact hole was used. It was found also that the contact resistance and junction leakage characteristics were improved by collimation sputtering when an adhesion layer was deposited in the contact holes with a high aspect ratio. It was concluded that this technology is advantageous in contact formation in devices with submicron structure

ISSN:8756-663X    

DOI:10.1002/ecjb.4420781208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThis paper discusses the amorphous Ti‐Si‐N diffusion barrier layer without crystalline grain boundaries. The Ti‐Si‐N layers were sputter‐deposited in Ar‐N2mixture gas using TiSi and TiSi2targets. In particular, films with a composition of Ti: Si: N = 1: 1: 1.4 were evaluated. It was confirmed that the films were amorphous and thermally stable. The stress of the films was low and compressive, where it was 0.28 GPa. The junction leakage current measurement indicated that the barrier characteristic was effective at 600°C. Therefore, it was concluded that the amorphous Ti‐Si‐N layer could be used as a barrier for Cu

ISSN:8756-663X    

DOI:10.1002/ecjb.4420781209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractA silicide process is indispensable to reduction of the parasitic resistance of deep submicron CMOS devices. The parasitic resistance degrades the operating speed of ultrafine gates, limiting development of further scale‐down CMOS devices. However, the conventional silicide process causes many problems, such as agglomeration, junction leakage and thermal instability, and cannot be used for mass production of deep submicron semiconductor devices. The limitations of conventional Ti, Pi, Ni, and Co silicide processes are investigated and analyzed, and it is found that a TiN‐capped Co silicide process is suitable for fabricating 0.1‐μm CMOS d

ISSN:8756-663X    

DOI:10.1002/ecjb.4420781210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY