An Effective Modeling Framework for the Analysis of Interconnects Subject to Line-Edge Roughness

Abstract

Abstract-This letter proposes a complete and efficient simulation framework to assess the effects of line-edge roughness appearing in on-chip lines. The modeling approach consists of three steps. First, a stochastic macromodel is created for the per-unit-length RLGC parameters of the line. Secondly, random conductor edge profiles are generated using randomized splines. These are combined with the stochastic macromodel to readily provide place-dependent RLGC parameters. Finally, the resulting nonuniform transmission line is analyzed by means of a fast and accurate perturbation technique. To validate the proposed approach, a statistical analysis of the response of a coupled inverted embedded microstrip line is carried out for different roughness parameters.

Analysis of coupled exponential microstrip lines by means of a multi-step perturbation technique

“…The blue lines provide a reference computed by discretizing the line into 1001 uniform sections. The dashed black line is the result obtained with the perturbation technique with two steps only (K = 2), as from the previously proposed framework in [13]- [15]. There is an appreciable lack of accuracy, especially on the magnitude of the voltage along the active conductor and on the phases of both voltages.…”

“…A two-step perturbation technique was proposed as an accurate and more general approach [13] and applied to the analysis of the effects of fiber weave [14] and line-edge roughness [15]. The nonuniformity is interpreted as a perturbation of a uniform line with averaged per-unit-length (p.u.l.)…”

Analysis of Nonuniform Transmission Lines With an Iterative and Adaptive Perturbation Technique

“…parameters is limited by geometrical constraints, thus rendering the second-order perturbation sufficiently accurate [42]- [44]. On the contrary, the variations of wire positions in TWPs or in nonuniform cable harnesses, as considered in this paper, result in a more severe variation of the p.u.l.…”

A perturbative approach to predict eye diagram degradation in differential interconnects subject to asymmetry and nonuniformity

“…In addition, manufacturing variability can introduce a geometrical asymmetry in the conductor shape as well as further nonuniformity causing, e.g., the shape to vary along the direction of propagation [2]. Asymmetry causes the propagation characteristics along the two line conductors to differ.…”