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Kilby integrated circuit demonstration 2026-10-18
In his 2000 lecture, Jack St. Clair Kilby describes an August 1958 comparison circuit made from separate silicon elements. Resistors were cut and etched; capacitors came from diffused, metallized semiconductor wafers. It tested whether semiconductor elements could perform all the required functions, but was still a discrete circuit. For the September prototype he used already diffused germanium material with contacts, cut into bars, and hand-applied wax masks to define a transistor and a distributed resistor-capacitor region. Applying supply power produced an oscillation.[ref]
Turning Potential into Realities: The Invention of the Integrated Circuit (Nobel Lecture) by Jack St. Clair Kilby. Kilby's 2000 Nobel lecture, ChemPhysChem reprint (2001), pp. 486–487, separate-element comparison and oscillator preparation
An inspected eyewitness interview describes the germanium on a microscope slide with protruding wires; changing its connections changed the oscilloscope display from a straight line to a sinusoid. This supplied a qualitative connected/disconnected comparison, not a calibrated record of amplitude, loading or repeatability.[ref]
Oral History of Jay W. Lathrop. Oral History of Jay W. Lathrop, recorded 7 May 2009, p. 11, demonstration and oscilloscope comparison
The inference was feasibility: integrated semiconductor elements could cooperate as an operating electrical circuit. The hand-wired germanium prototype did not yet supply the deposited integrated circuit interconnects of Robert Noyce's silicon design. Nor does a working prototype establish manufacturing yield or long-term reliability.