1949

Integrated Circuit

Werner Jacobi (1904–1985), Jack Kilby (1923–2005), Robert Noyce (1927–1990)

Prior to the widespread deployment of integrated circuits, electronic devices like computers were made of discrete transistors. Each transistor came in a small can about the size of a pea, with three wires attached. These transistors would be soldered onto a printed circuit board. A computer of this era might have used several thousand transistors, soldered onto ten or more boards each the size of a piece of paper or larger. The boards of the simplest computers filled a box the size of a filing cabinet. The largest computers filled entire rooms. Computers were big, heavy, expensive, slow, and power hungry as a result.

The integrated circuit changed all of this. In 1949, German engineer Werner Jacobi proposed the first integrated circuit-like device. In 1958, electrical engineer Jack Kilby, working for Siemens, demonstrated the first working integrated circuit, and shortly after, Robert Noyce improved upon it by creating a silicon chip. Integrated-circuit technology transformed the computer and electronics industries.

The basic idea is simple and it starts with a polished silicon wafer sliced from a large silicon crystal grown in a lab. Three things then happen to the wafer: 1) parts of the wafer’s surface can be selectively doped with the substances used to create transistors, 2) layers of oxide can be grown to act as insulators, and 3) metal wires can be deposited to connect transistors together. The engineering has gotten increasingly sophisticated in recent years, with many metal layers and 3D transistors making smaller, more complicated circuits possible.

Integrated circuits are one of the best examples of incremental improvement in engineering. Engineers have radically improved cost, capabilities, and performance over time and the pace of improvement has been staggering. Every two years, the number of transistors on a chip has doubled—a rate known as Moore’s Law. So today’s microprocessors have billions of transistors running efficiently at low voltages and high speed. We all benefit from the integrated circuits in our smart phones, tablets and home computers.

SEE ALSO ENIAC—The First Digital Computer (1946), Transistor (1947), Microprocessor (1971), Smart Phone (2007), Tablet Computer (2010).

Close-up of a chip in an integrated circuit.