21st Century Opportunities For Gigascale Integration (GSI)

Summary form only given. What are the critical limits that are most likely tlo determine how many billions of transistors we will manufacture in future commercially viable silicon chips? For nearly four decades, silicon microelectronics has progressed at an unmatched exponential pace in both performance and productivity. The switching energy or power-delay product of a binary transition has been reduced by about five decades and the number of transistors per chip has been increased by approximately eight decades, while the price range of a chip has remained nearly constant. The National Technology Roadmap for Semiconductors projects a 64 billion bit DRAM chip by 2010. Perhaps the most compelling question confronting the surging US$150 billion world-wide semiconductor industry is, "How much fiuther will the laws of physics (and economics) enable this progress to continue?" My current view is that early 21st century opportunities for gigascale integration (GSI) will be govemed by a hierarchy of theoretical and practical limits whose five levels can be codified as: 1) fundamental; 2) material; 3) device; 4) circuit; and 5) system. In this discussion I intend to review recent enhancements of this hierarchy and identify those critical limits that appear to present the most formidable challenges to continued progress toward GSI.