On-chip crosstalk mitigation for densely packed differential striplines using via fence enclosures

The measured crosstalk characteristics for close-packed via fence enclosed differential stripline structures in a standard digital CMOS process are reported. The transmission lines achieve a packing pitch of 16 μm of interconnect width per differential pair. The nearest neighbour far-end differential crosstalk is measured to be better than -43 dB and the near-end differential crosstalk is better than -37 dB below the drive signal at frequencies up to 20 GHz for 600 μm lines. This is sufficient for use in high-density, high-speed analogue and digital integrated circuits.