By In 1965, Dr. Gordon Moore was asked to write an article describing the future of electronics for the 35th anniversary issue of Electronics magazine. At that time, integrated circuits (IC) were four years old, planar transistors were only six years old, Moore was the director of the research and development laboratories at Fairchild Semiconductor, and they were creating state-of-the-art ICs with 60 components. In this seminal article, Cramming More Components onto Integrated Circuits, (Electronics; volume 37, no. 8; April 19, 1965), Moore postulated his now-famous law: The number of transistors that can be integrated on a chip will grow exponentially by a factor of two.

But thats not really what he said, and he didnt postulate anything. What he did say was the complexity for minimum component costs of ICs had increased at a rate of log 2 per year, and over the short term (10 years), this rate could be expected to continue. He further predicted that by 1975 the number of components per integrated circuit for minimum cost will be 65,000. Moore observed the cost per component is inversely proportional to the number of componentsto a point. As components are added, a point is reached where costs per component begin to rise. That point is the minimum component cost and is determined by the state of the technology at the time. In 1965, it was 50 components per circuit.

So What Is a Planar Transistor?
Digital computers rely on switches that represent two statesbinary 1 or binary 0, on or off. OK, it really is more complicated than that in the real world. On and off are represented by voltage differentials, not absolutes, but for our purpose, on or off will work just fine. The first electronic digital computers used vacuum tubes to function as binary switches. Then, in 1947, Bell Laboratories invented the transistor, a device that was able to control the flow of electricity through a solid material like silicon; hence, the term solid state. Silicon is a substance known as a semiconductor, which means, depending on its state, it either may act as a conductor or an insulator. A basic transistor consists of an emitter, a base, and a collector. Current flows from the emitter to the collector through the base. When a specific voltage (usually negative) is applied to the base, free electrons are repelled, changing the base from a conductor to an insulator. This establishes a method for controlling binary signalsno voltage to the base one state, negative voltage to the base another state. On or off. 1 or 0.