The Invention of the Modern Field-Effect Transistor
This 1960 patent describes the fundamental structure of the MOSFET, the tiny electronic switch that powers every modern computer processor.
Original patent title: “Electric field controlled semiconductor device”
This 1960 patent describes the fundamental structure of the MOSFET, the tiny electronic switch that powers every modern computer processor. Granted to Bell Telephone Laboratories Inc in 1963 with 2 claims and 37 forward citations, and it is now in the public domain.
Key facts
Coverage
What does this patent actually cover?
The patent describes a semiconductor device that uses an electric field to control the flow of current between two regions of the same conductivity type, separated by a region of the opposite type. By placing a dielectric (insulating) layer over the surface and applying a voltage, the device creates an electric field that modulates the conductivity of the channel between the two P-N junctions. This mechanism allows a small input voltage to act as a gate, effectively turning the flow of electrons on or off, which is the basic requirement for binary logic in digital circuits.
The gap
What does this patent NOT cover?
- Does not cover bipolar junction transistors (BJTs) which rely on current injection rather than electric field control.
- Does not cover vacuum tubes or other non-semiconductor switching technologies.
- Does not cover specific manufacturing lithography techniques used to build these devices at scale.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The innovation was using an insulating dielectric layer to isolate the control gate from the semiconductor, preventing current leakage into the gate while still allowing the electric field to influence the channel.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Modern computer CPUs (Intel Core, AMD Ryzen)
Smartphone processors (Apple A-series, Qualcomm Snapdragon)
Computer memory chips (DRAM and Flash storage)
Why it matters
The bigger picture
This is the foundational patent for the Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). It is arguably the most important patent in the history of computing, as it enabled the miniaturization of transistors that allowed for the creation of integrated circuits and microprocessors.
Filed
May 31, 1960
Granted
August 27, 1963
Market context
Who's building on this
Companies in this space
Every major semiconductor manufacturer, including Intel, TSMC, Samsung, and NVIDIA, builds upon the foundational physics described in this patent. The basic MOSFET architecture remains the primary building block for virtually all modern logic gates.
Market impact
This patent enabled the transition from bulky, power-hungry vacuum tubes and early transistors to the dense, efficient integrated circuits that define the information age. It triggered the rapid scaling of computing power described by Moore's Law, effectively creating the entire modern semiconductor industry.
Claim 1 — Plain English
What this patent covers
The patent describes a semiconductor device that uses an electric field to control the flow of current between two regions of the same conductivity type, separated by a region of the opposite type. By placing a dielectric (insulating) layer over the surface and applying a voltage, the device creates an electric field that modulates the conductivity of the channel between the two P-N junctions. This mechanism allows a small input voltage to act as a gate, effectively turning the flow of electrons on or off, which is the basic requirement for binary logic in digital circuits.
The clever bit
The innovation was using an insulating dielectric layer to isolate the control gate from the semiconductor, preventing current leakage into the gate while still allowing the electric field to influence the channel.
What it does not cover
- Does not cover bipolar junction transistors (BJTs) which rely on current injection rather than electric field control.
- Does not cover vacuum tubes or other non-semiconductor switching technologies.
- Does not cover specific manufacturing lithography techniques used to build these devices at scale.
Patent Journey
From filing to expiry
PatentBrief Score
Impact Score
Early stage
Citation count
32/40
Moderately cited
Claim breadth
1/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$13K – $40K
Midpoint $25K · expired or expiring · industry ×1.4
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
The original legal language
Original claims
2 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Dawon, K. (1963). The Invention of the Modern Field-Effect Transistor (U.S. Patent No. 3,102,230). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/3102230/mosfet-field-effect-transistor
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
Embed
Add this patent to your site
Drop this plain-English patent card into any blog post or article — free, no signup. It always links back to the full breakdown here.
<div data-patentlens-widget data-patent-number="US3102230"></div> <script src="https://patentbrief.org/embed.js" async></script>
Stay in the loop
Get a weekly digest of new patents.
One email per week. No spam. Unsubscribe anytime.
Keep exploring
Related patents you should know
US 4683195 · 1987
How to Make Billions of Copies of a DNA Segment
This patent describes the Polymerase Chain Reaction (PCR), a method to rapidly create many copies of a specific piece of DNA or RNA, enabling its detection and analysis.
Cetus Corp
US 8697359 · 2014
How to Edit Genes in Human Cells Using an Engineered CRISPR System
This patent describes an engineered CRISPR-Cas9 system for precisely cutting DNA in eukaryotic cells to change how genes work, opening the door for gene editing in complex organisms.
Massachusetts Institute of Technology
US 7657849 · 2010
How the iPhone's Slide-to-Unlock Gesture Works
Apple's 2010 patent describes unlocking a device by dragging a specific graphical image across the touchscreen along a predefined path, a gesture that became iconic with the original iPhone.
Apple Inc
US 4733665 · 1988
How Doctors Implant a Permanent Stent Using a Balloon
This patent describes the method for placing a permanent, expandable wire mesh tube inside a blood vessel or other body tube using a balloon-tipped catheter to widen it and keep it open.
Expandable Grafts Partnership
US 4405829 · 1983
How RSA Public-Key Encryption Keeps Digital Messages Secret
This patent describes the foundational RSA algorithm, a method for securely sending messages where anyone can encrypt a message using a public key, but only the intended recipient can decrypt it using a secret private key.
Massachusetts Institute of Technology
US 4575330 · 1986
How 3D Printers Build Objects Layer by Layer from Liquid
This patent describes the foundational method for 3D printing, where a machine builds a three-dimensional object layer by layer by hardening a liquid material with light or other energy.
UVP Inc
Semantically similar
You might also find these interesting
US 2569347 · 1951 · Bell Telephone Laboratories Inc
The Invention of the Junction Transistor
US 2524035 · 1950 · Bell Telephone Laboratories Inc
The Invention of the Transistor
US 3387286 · 1968 · International Business Machines Corp
How Robert Dennard Invented the One-Transistor DRAM Memory Cell
US 2981877 · 1961 · Fairchild Semiconductor Corp
How Robert Noyce Invented the Modern Integrated Circuit
More to explore
More in Semiconductors & Chips
US 5563422 · 1996 · Nichia Chemical Industries Ltd
How Nichia Created the First Practical Blue LED Electrodes
US 2981877 · 1961 · Fairchild Semiconductor Corp
How Robert Noyce Invented the Modern Integrated Circuit
US 2569347 · 1951 · Bell Telephone Laboratories Inc
The Invention of the Junction Transistor
US 2524035 · 1950 · Bell Telephone Laboratories Inc
The Invention of the Transistor
New to patents?
Common Questions
Frequently Asked Questions
What does The Invention of the Modern Field-Effect Transistor cover?
This 1960 patent describes the fundamental structure of the MOSFET, the tiny electronic switch that powers every modern computer processor.
Who owns patent US 3102230?
Bell Telephone Laboratories Inc owns this patent, granted in 1963.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 3102230 cited by?
This patent has been cited by 37 later patents that build on its ideas.
What problem does this patent solve?
This is the foundational patent for the Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). It is arguably the most important patent in the history of computing, as it enabled the miniaturization of transistors that allowed for the creation of integrated circuits and microprocessors.
What does this patent NOT cover?
Does not cover bipolar junction transistors (BJTs) which rely on current injection rather than electric field control.
Same assignee
More from Bell Telephone Laboratories Inc
Patent monitoring