8. For decades, the semiconductor industry has measured its progress against a technology roadmap that predicted the progress of such things as feature size and chip densities. In late November, the industry experts who put together the annual roadmap warned chip makers that device shrinks and other tools used to hike the performance of silicon transistors could hit fundamental process limits much earlier than previously expected.
The industry's 2001 technology roadmap concluded that completely new transistor structures must be developed as potential replacements for traditional CMOS devices within the next six-to-nine years because integrated circuit manufacturers were accelerating process shrinks.
In microprocessors, for example, leading suppliers have increased greatly the physical scaling of transistor gate lengths using post-lithographic process techniques, such as selective etching. The aggressive gate-length shrinks increase MPU speeds, but the practice also is causing lithography and current semiconductor materials to run out of steam sooner than expected, the experts concluded.
Chip makers were urged to accelerate their development of completely new transistor structures. Three basic types were identified in the 2001 roadmap: ultra-thin body SOI (silicon-on-insulator) transistor; band-engineered transistor; and double-gate transistor.
Another surprise in the 2001 roadmap was the "deceleration" in the development of low-k dielectrics as next-generation insulators in IC interconnects. Chip makers have come up with various design tricks to get around the need to switch to new low-k dielectric films while the industry struggles to develop a better replacement for silicon dioxide.
(Return to 2001 Top 10 list or go to No. 9).