Interconnect and substrate structure for gigascale integration

Signal wave propagation properties for a high-speed gigascale integration (GSI) system LSI featuring an operation frequency of more than 10 GHz have been analyzed and discussed by solving the cylindrical Maxwell's equations directly using a stacked coaxial structure. The results give us a good perspective and enable us to predict the ultrahigh-speed and miniaturized interconnect characteristics. The metal substrate structure is essential to suppress the substrate surface potential fluctuations and the substrate-induced signal attenuation and delay. The gas-isolated interconnect structure can effectively reduce the signal attenuation and delay. The combination of the gas-isolated interconnect and the metal substrate structure is the most promising solution for an interconnect and a substrate in GSI.