How Jack Kilby Invented the First Integrated Circuit

Texas Instruments' 1959 patent for the first integrated circuit, which combined transistors and resistors on a single piece of semiconductor material.

What it covers

This patent describes the fundamental structure of an integrated circuit, or a microchip. It explains how to build multiple electronic components, specifically transistors and resistors, directly into a single wafer of semiconductor material like germanium or silicon. By layering regions of different electrical conductivity types—creating PN junctions—and connecting them with conductive paths on the surface, the design allows an entire circuit to exist on one small piece of material rather than using bulky, separate components wired together. This architecture is the ancestor of every modern processor.

What it doesn't cover

• —Does not cover the use of non-semiconductor materials for building circuit components.
• —Does not cover vacuum tube-based circuit designs.
• —Does not cover specific manufacturing lithography techniques used to etch these patterns.
• —Does not cover multi-chip modules where separate dies are packaged together.

The clever bit

Kilby realized that if you could make a transistor on a semiconductor, you could also make a resistor or capacitor out of the same material, eliminating the need for external wiring between them.

Why it matters

This is the 'Big Bang' of the modern computing era. Before this, engineers had to solder individual components together by hand, which was unreliable and limited how small a computer could be. This patent proved that complex electronics could be miniaturized, enabling the development of everything from pocket calculators to the smartphone in your hand.

Real-world examples

• 1.The original Texas Instruments Solid Circuit
• 2.Early pocket calculators
• 3.Modern microprocessors
• 4.Memory chips