Normal and superconductor coplanar waveguides with 100 nm line width

High speed high package density integrated circuits require a hierarchy of interconnections with small and large cross sections where the smallest linewidth approaches the 100 nm range. Attenuation and delay of superconducting interconnections down to the order of the London penetration depth for 50 Ω and higher characteristic impedances are compared with normal conducting ones near 20 GHz. Symmetrical coplanar waveguides with polycrystalline aluminum and niobium and c-axis oriented Y₁Ba₂Cu₃O _7-δ on substrates with a dielectric constant of about 12 are chosen to demonstrate basic properties mainly at 77 K and 4.2 K. Simulated quality factors are checked by measurements down to 1000 nm line width