You can freely build on How Jack Kilby Invented the First Integrated Circuit

What this patent 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 is now free to use

All 1 claims of US 3138743 are in the public domain. Specifically:

• Claim 1: IN AN INTEGRATED CIRCUIT HAVING A PLURALITY OF ELECTRICAL CIRCUIT COMPONENTS IN A WAFER OF SINGLE-CRYSTAL SEMICONDUCTOR MATERIAL, A PLURALITY OF JUNCTION TRANSISTORS DEFINED IN THE WAFER, EACH TRANSISTOR — 1 specific element

The 0 dependent claims add narrowing limitations and are also free.

What is NOT covered

Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.

• 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.

Who is building on this today

Every major semiconductor company, including Intel, TSMC, Samsung, and NVIDIA, builds directly upon the foundational principles of integrating multiple components onto a single semiconductor die established by this patent.

Products built on expired version of this technology

How to cite this patent in your documentation

Texas Instruments Inc. US Patent 3138743. Miniaturized electronic circuits. Granted 1964, expired 1981. Now in the public domain.

Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.

PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.