Computer History MuseumSemiconductor History

1961 - Silicon Transistor Exceeds Germanium Speed

Computer architect Seymour Cray funds development of the first silicon device to meet the performance demands of the world’s fastest machine.

Computer architect Seymour Cray had worked with General Transistor Corporation’s germanium transistors at Univac. On founding Control Data Corporation in 1957 with William Norris, Cray asked General Transistor to develop a fast switching germanium device for the CDC 1604 that in 1960 became the first commercially successful large-scale transistor machine for scientific computing.

With the goal of building the world’s fastest supercomputer, Cray required a transistor that switched in less than 3 nanoseconds while operating in a high temperature environment created by hundreds of thousands of devices operating in close proximity. Early silicon transistors offered superior operation to germanium at elevated temperature but were too slow for many computer designs.

Cray awarded Fairchild Semiconductor a $500,000 development contract to build a new transistor for the CDC 6600. Jean Hoerni met the specification by combining "gold-doping" - the addition of gold impurities - together with the new epitaxial deposition process. (1960 Milestone) The 2N709 (FT-1310) n-p-n device was introduced in July 1961 as the first silicon transistor to exceed germanium speed.

Each CDC 6600 used 600,000 transistors packaged in a unique cordwood-style module configuration to minimize connecting wire lengths. In 1964 the company placed "one of the largest single orders in the history of the semiconductor industry" with Fairchild for over 10 million devices. Scientific Data Systems was another early adopter of high-speed silicon transistors for logic applications in the Sigma series computers.



Contemporary Documents

Hoerni, Jean A. "Selective control of electron and hole lifetimes in transistors," U. S. Patent 3,184,347 (Filed July 19, 1962. Issued May 18, 1965).

Fogelsong, R. L. "The Design of High Speed All Transistor Logic Circuits," Fairchild Silicon Transistors, Application Data APP-49 (December 1962)

More Information

Thornton, James E. Design of a Computer: The Control Data 6600. (Glenview, IL: Scott, Foresman and Co., 1970)

Sah, C.T., "Evolution of the MOS transistor-from conception to VLSI" Proceedings of the IEEE, Vol. 76, Issue 10 (Oct 1988) pp: 1280-1326.

Moore, G. E., "The Role of Fairchild in Silicon Technology" Proceedings of the IEEE, Vol. 86, Issue 1 (1998) pp. 53-62.