Transistor
The transistor is the fundamental building block of modern electronic devices, and is ubiquitous in modern electronic systems. Julius Edgar Lilienfeld patented a field-effect transistor in 1926 but it was not possible to actually construct a working device at that time. The first practically implemented device was a point-contact transistor invented in 1947 by American physicists John Bardeen, Walter Brattain, and William Shockley. The transistor revolutionized the field of electronics, and paved the way for smaller and cheaper radios, calculators, and computers, among other things. The transistor is on the list of IEEE milestones in electronics, and Bardeen, Brattain, and Shockley shared the 1956 Nobel Prize in Physics for their achievement.
Invention of the integrated circuit
In May 1952, Sidney Darlington filed a patent application in the United States for a structure with two or three transistors integrated onto a single chip in various configurations; in October 1952, Bernard Oliver filed a patent application for a method of manufacturing three electrically connected planar transistors on one semiconductor crystal. On May 21, 1953, Harwick Johnson filed a patent application for a method of forming various electronic components – transistors, resistors, lumped and distributed capacitances – on a single chip. Johnson described three ways of producing an integrated one-transistor oscillator. All of them used a narrow strip of a semiconductor with a bipolar transistor on one end and differed in the methods of producing the transistor. The strip acted as a series of resistors; the lumped capacitors were formed by fusion whereas inverse-biased p-n junctions acted as distributed capacitors. Johnson did not offer a technological procedure, and it is not known whether he produced an actual device. In 1959, a variant of his proposal was implemented and patented by Jack Kilby.