Arsalan Alam

An Unconditionally Stable FDTD Model for Crosstalk Analysis of VLSI Interconnects

In this paper, an unconditionally stable finite-difference time-domain (US-FDTD) model is proposed for the crosstalk noise analysis of coupled very large scale integration interconnects. The accuracy of the proposed model is validated against the conventional FDTD model and HSPICE. It is observed that the proposed model is as accurate as the conventional FDTD and HSPICE. It is also observed that the stability of the proposed model is not constrained by the Courant-Friedrichs-Lewy stability condition. Depending on the time-step size, the proposed model can be up to 100× faster than the conventional FDTD.

Signal integrity improvement with peripherally placed MWCNTs in mixed CNT bundle based TSVs

This paper presents a novel method to reduce the crosstalk induced delay in coupled carbon nanotube (CNT) bundle based through silicon vias (TSVs). A unique structure of mixed CNT bundled (MCB) TSV is proposed, wherein multi-walled CNTs (MWCNTs) are placed peripherally to the centrally located single-walled CNTs (SWCNTs). An electrical equivalent model is employed for analyzing these MCB configurations. The analysis demonstrates that a significant reduction in propagation delay and crosstalk induced delay is achieved for a larger number of peripheral layers containing MWCNTs. Moreover, the crosstalk reduction is prominently higher for MWCNTs with more number of shells in longer TSVs. For TSV heights from 30 to 120μm, an average reduction of out-phase, in-phase and propagation delays of 17.54%, 19.73% and 14.45%, respectively, is observed using novel MCB instead of conventional SWCNT bundle based TSV.

Performance analysis of single- and multi-walled carbon nanotube based through silicon vias

This paper presents a comparative analysis for power, delay and bandwidth performance between single- (SWCNT) and multi-walled (MWCNT) carbon nanotube bundle filled through silicon vias (TSVs). A comprehensive and accurate electrical equivalent model of CNT bundled TSV is presented that takes into account the MOS effect of silicon substrate. The transfer function of driver-TSV-load (DTL) system is obtained by representing the via line with equivalent single conductor (ESC) model of CNT bundle based TSVs. Using absolute frequency response, it is observed that the bandwidth of 10-shell MWCNT bundled TSV is larger in comparison to the SWCNT bundle, 4-shell MWCNT and 8-shell MWCNT bundle based TSVs. Moreover, a 10-shell MWCNT bundle demonstrates substantial reduction in delay and power dissipation in comparison to the SWCNT bundle based TSV.

“FlexTrate ^TM” — Scaled Heterogeneous Integration on Flexible Biocompatible Substrates Using FOWLP

We have developed a novel fan-out wafer level packaging (FOWLP) technology for high-performance and scalable flexible and biocompatible substrates that we call FlexTrate (TM). We demonstrate the technology with the assembly of 1-mm-sqaure 625 (25 by 25) Si dielets on a biocompatible Polydimethylsiloxane (PDMS). By using the new FOWLP technology, die-die interconnects with a pitch of 10 mm or less were implemented on the array of the Si dielets embedded in the PDMS.