High-Performance Interconnects With Reduced Far-End Crosstalk for High-Speed ICs and Communication Systems

This article analyzes the far-end crosstalk (FEXT) of high-density interconnects and implements new designs of high-performance tabbed lines with significantly reduced FEXT. The FEXT of traditional coupled lines with and without integrated tabs are fully analyzed. Closed-form formulas are applied to calculate the capacitance and inductance matrices of the coupled lines and the tabbed routing structures, leading to an accurate evaluation of the FEXT. Designs in 3-D configuration and integration of magnetic and dielectric thin films are proposed to either increase the mutual capacitance or increase the self-inductance within the coupled interconnects for further reduction of FEXT. To validate the proposed designs, structures are implemented on silicon wafers with the standard photolithography process, and their performance in terms of S-parameters and eye diagrams has been characterized and compared. The measured FEXT behaviors of the implemented interconnects show that the proposed designs reduce the FEXT at 10 GHz of the original coupled lines from −10.99 to −17.44, −25.19, and −25.58 dB. This article provides efficient methods and designs to improve FEXT of high-speed and high-density interconnects.