Gigabit logic a review

The current state of gigabit logic is presented. Recent developments have made a significant contribution to this field, and it is the purpose of this´ work to compare these new developments with the more traditional approaches. The relationships between device and circuit parameters are derived in an Appendix, and these relationships are used to explore the conditions which must be satisfied by the devices if they are to offer gigabit logic operation. To meet large system requirements, it is shown that the highest levels of integration must be used: for a given complexity the requirements of individual components, e.g. power dissipation, parameter tolerances, are derived. The various circuit types, including the recent results from HEMTs and submicron silicon MOSFETs, are discussed. For the purposes of this review, only those devices which have already been integrated are studied; thus bipolar III-Vs, permeable base transistors and other similar devices are not discussed. The developments in submicron silicon present a challenge to GaAs speed superiority. This potential superiority forms the basis of the discussion in the paper, together with a projection for the future.