Comparison of GaAs device approaches for ultrahigh-speed VLSI

The superior electronic properties of gallium arsenide and related III-V compound semiconductors, as compared with silicon, have made them of great interest for ultrahigh-speed logic applications. Many ingenious device structures have been proposed or demonstrated for utilizing the advantageous electron dynamics of GsAs to achieve ultralow propagation delay and/or ultralow power-delay product (dynamic switching energy) logic circuits. The intent of this paper is to give an overview of some of these GaAs device approaches, including their principal, attractions, expected performance levels, etc. (Much more detailed analyses of some of these structures are presented in other papers in this issue.) This overview is extended to a comparison of the relative merits of these GaAs device approaches vis-à-vis their applicability for achieving ultra high-speed logic of large-scale integration (LSI) or very large-scale integration (VLSI) levels of complexity (as opposed to simpler SSI/MSI applications).