G. Angenieux

A simple and systematic method for the design of tapered nonlinear transmission lines

In this paper, we present an original method, simple to implement, rapid and systematic for the conception of Nonlinear Transmission Lines (NLTL) for shock wave generation. This method is based on SPICE simulations and allows the synthesis of hybrid or monolithic NLTLs.

Impact of design on high frequency performances of advanced MIM capacitors using SiN dielectric layers

High-frequency characterizations of ultra thin 32 nm PECVD Si3N4 dielectric in an advanced metal-insulator-metal (MIM) capacitors are presented, with focus on the impact of design on the performance of MIM capacitors. Frequency dependent capacitance has been extracted over a wide range of frequency bandwidth. An equivalent model circuit of capacitors including four parameters was developed to explain this behavior. The results have been compared with the values obtained from a 3-D electromagnetic modeling. A specific chart has been introduced to predict the electrical performance of new MIM capacitor designs.

Capacitive impacts of dummies on interconnect propagation performances for integrated circuits of the 65 nm node and below

The placement and size of square dummies degrade electrical performances mainly in terms of interconnect capacitance and propagation delay time. Electrical parameters for an isolated interconnect are obtained in a whole spectrum (up to 40 GHz) by electromagnetic modeling. Parasitic effects could be traduced by a fictitious increase of the relative permittivity k-value of inter-level dielectric cutting down performances of porous ULK integration for future 65 and 45 nm technology nodes. The capacitive effect of dummies on the interconnect test structure with a dielectric at k=2.7 was found, in some situations, to be equivalent to that obtained with a dielectric at k=3.2 without dummies. The capacitive effect of dummy distribution was also shown to be generally inhomogeneous, dramatically depending on dummy size and local interconnect design. However, an optimal size of dummies could be determined, leading to an homogeneous capacitive degradation effect, independent of the local interconnect dummy surrounding situation.

Optimization of signal propagation performances in interconnects of the 45 nm node by exhaustive analysis of the technological parameters impact

Due to the continuous shrink of technology dimensions, parasitic propagation delay time and crosstalk at interconnect levels increasingly affect overall circuit performances. New materials, processes and architectures are now required to improve BEOL performances. A rigorous high-frequency electromagnetic approach including the scattering effects on Cu line resistance was developed for coupled narrow interconnects to analyze the actual benefits of these innovations for different signal types covering application range from logic to I/O. Effects of advanced metallization (ALD thin barriers), low-k insulators (porous ULKs, low-k barriers), and innovative architectures (hybrid stacks, air gaps, self-aligned barriers) on signal propagation performance were quantified, resulting in an effective process selection for the 45 nm technological node and below.

Multimodal variational analysis of quasiplanar waveguide discontinuities

Multimodal variational analysis will be presented for step discontinuity of some commonly used quasiplanar structures. Appreciable reduction in the computation time and computer memory space can be obtained by handling differently the modes which can be accessible from a certain distance to the discontinuity plane and those localized. An analysis program developed in FORTRAN on a PC computer will be applied to microstrip, finline and coplanar discontinuities, and compared to previously published results and experiments.

Impact of Design on High-Frequency Performance of Advanced MIM Capacitors Using Si

High-frequency characterizations of ultra thin 32 nm PECVD Si3N4 dielectric in an advanced metal-insulator-metal (MIM) capacitors are presented, with focus on the impact of design on the performance of MIM capacitors. Frequency dependent capacitance has been extracted over a wide range of frequency bandwidth. An equivalent model circuit of capacitors including four parameters was developed to explain this behavior. The results have been compared with the values obtained from a 3-D electromagnetic modeling. A specific chart has been introduced to predict the electrical performance of new MIM capacitor designs.

_{3}

An accurate and simple method to in-situ characterize the dielectric constant of insulator thin films is developed. Optimized devices under test are capacitive patches where insulator film is set in the future operational configuration. Dielectric constant is extracted by an optimization procedure based upon subnanosecond time domain reflectometry measurement and simulation. /spl epsiv//sub r/ is given into a 100 MHz-10 GHz frequency bandwidth.

N

A fast and accurate method characterizing embedded and coupled transmission lines is presented. Such multilayered structures are used to realize integrated directional couplers. The method requires simple two-ports network analyzer S-parameter measurements performed with a TRL calibration. Extractions of inductance and capacitance matrices are obtained in the [0.5-3.5] GHz frequency bandwidth. Comparisons with electromagnetic modeling results are given.

_{4}

The authors present a full-wave description of propagation and losses for some quasi-planar transmission lines using a quasi-analytical solution. The latter is derived from a modified transverse resonance method (MTRM), in which analytical preprocessing has been introduced. The quasi-static contribution is obtained by an entirely analytical solution, making the resultant system of linear equations very efficient. The resistive boundary conditions and the complex substrate permittivity are taken into account in an intrinsic manner, leading to an accurate determination of dielectric and conductor losses in lossy transmission lines. Theoretical and experimental results are presented for a lossless coplanar waveguide and a lossy microstrip line, respectively.<<ETX>>

Dielectric Layers

This paper deals with the characterization of lossy transmission lines. The method developed here delivers the complex propagation coefficient ¿ and the characteristic impedance of any arbitrary characteristic impedance transmission line, embedded in an arbitrary environment. This approach is based upon time domain analysis, made with a commercial sampling oscilloscope. The method only requires the realization of two transmission lines of different lengths and allows a complete correction for the systematic errors of the measurement system. The problem of the random errors is also addressed and a sensitivity study on the effects of random errors is made. The method is demonstrated with microstrip transmission lines. A comparison of the developed technique with a classical frequency domain extraction is also carried out.