Computer History MuseumSemiconductor History

1968 - Silicon Gate Technology Developed for ICs

Federico Faggin and Tom Klein improve the reliability, packing density, and speed of MOS ICs with a silicon-gate structure. Faggin designs the first commercial silicon-gate IC – the Fairchild 3708.

Robert Kerwin, Donald Klein and John Sarace at Bell Labs improved the speed, reliability, and packing density of MOS transistors (1960 Milestone) by replacing the aluminum metal gate electrode with a polycrystalline layer of silicon in 1967. Boyd Watkins described a similar self-aligned, silicon-gate structure at General Microelectronics in 1965 but patent filing was delayed until 1969. As project leader, Federico Faggin worked with Tom Klein at Fairchild R&D to commercialize the technology for ICs. Faggin then redesigned an existing p-channel metal-gate 8-channel analog multiplexer circuit using the new technology and in 1968 Fairchild introduced the first silicon-gate IC, the 3708.

Following Fairchild’s proof of concept, Intel pursued silicon-gate as the primary technology for semiconductor memories as it delivered 3 to 5 times faster speed in half the chip area of conventional MOS. Intel’s first commercial MOS device, the 1101 256-bit RAM, was introduced in 1969. Faggin joined Intel in 1970. By adding a buried contact and other process enhancements for logic applications he was able to design the 4004 microprocessor CPU to fit on a manufacturable die size. (1971 Milestone)

Intel’s pioneering work in transferring silicon-gate to production presented many challenges but gave the company a significant competitive lead by permitting the early introduction of high density dynamic RAMs. (1970 Milestone) It also enabled the development of EPROM memories (1971 Milestone) that could not be accomplished economically with metal gate technology. Within five years silicon-gate MOS had become the industry standard process for new IC product development replacing bipolar technology in all but the highest speed applications.



Contemporary Documents

Kerwin, Robert E., Klein, Donald L., Sarace, John C. "Method for making MIS structures," U. S. Patent 3475234 (Filed March 27 1967. Issued October 28, 1969).

Watkins, Boyd G. and Selser, Michael J. "Semiconductor Device and Method for Producing Same," Canadian Patent 825844 (Filed September 5, 1967. Issued October 21, 1969). See also U. S. Patent 3576478 (Filed July 22, 1969. Issued April 27, 1971).

Sarace, J. C., Kerwin, R. E., Klein, D. E., and Edwards, R. "Metal-nitride-oxide-silicon field-effect transistors, with self-aligned gates," Solid-State Electronics, Vol. 11, Issue 7 (July 1968) pp. 653-660.

Faggin, F., Klein, T., and Vadasz, L. "Insulated gate field effect transistor integrated circuits with silicon gates," IEEE Transactions on Electron Devices, Vol. 16, Issue 2 (Feb 1969) p. 236.

Faggin, F., Klein, T. "Silicon Gate Technology," Solid State Electronics, Vol. 13 (1970) pp. 1125-1144.

More Oral Histories

Faggin, Federico (Fairchild, Intel) The Silicon Genesis Interviews (3.3.1995). Department of Special Collections, Stanford University Libraries, Stanford, California.

Faggin, Federico Electrical Engineer, an oral history conducted in 2004 by John Vardalas, IEEE History Center, Rutgers University, New Brunswick, NJ, USA.

More Information

Faggin, Federico and Klein, Thomas. "A faster generation of MOS devices with low thresholds is riding the crest of the new wave, silicon-gate IC’s," Electronics (September 29, 1969) pp. 88-94.

Vasdaz, L.L., Grove, A. S., Rowe, T. A., Moore, G. E. “Silicon Gate Technology,” IEEE Spectrum, Vol. 6 No. 10 (October 1969) pp. 28-35.