← The Big Questions
The Big Questions · 16 of 25

The Semiconductor Revolution

Billions of tiny switches that run the modern world

From one switch to billions

YearMilestone
1947Transistor invented at Bell Labs
1958–59First integrated circuits, by Kilby and Noyce
1965Moore's law: transistor counts double about every two years
1971Intel 4004: about 2,300 transistors
TodayTop chips: tens to hundreds of billions

A modern transistor is a few dozen atoms wide in places.

How a chip is made

  1. Purify siliconGrown into a large crystal and sliced into wafers
  2. Print patterns with lightLithography draws circuits smaller than a virus
  3. Add and etch layersDozens of layers of wiring and switches
  4. Test and packageEach wafer becomes hundreds of chips

A transistor

An electrical switch with no moving parts: on is 1, off is 0.

Where chips are

Phones and computers

Processors and memory

Cars

Dozens to thousands of chips per vehicle

Medicine

Scanners, monitors and pacemakers

AI

Specialized chips train and run models

Sources: Computer History Museum; Semiconductor Industry Association

Remember

Every digital device is built on transistors, tiny switches made by the billions on silicon.