Fix dollar signs + add descendants section

# [TECH] Integrated Circuit

**The Integrated Circuit (IC)** — a single semiconductor chip containing multiple transistors, resistors, and capacitors — was independently invented by Jack Kilby (TI, 1958) and Robert Noyce (Fairchild, 1959) and became the engine of the digital revolution.

## Overview

Before ICs, electronic systems were built from discrete components hand-soldered together. The IC allowed miniaturisation, cost reduction, and reliability improvements of orders of magnitude. Gordon Moore observed (1965) that transistor density doubles approximately every two years ("Moore's Law"), a trend that held for 50 years. The Intel 4004 (1971, 2,300 transistors) was the first commercial microprocessor; NVIDIA's H100 (2022) contains 80 billion transistors. The foundry model (TSMC, 1987) industrialised IC manufacturing to the most complex manufacturing process ever devised.

## Key Actors

- **Companies**: Texas Instruments (1951), Fairchild Semiconductor (1957), Intel (1968), TSMC (1987), Samsung (1969), NVIDIA (1993)
- **Inventors**: Jack Kilby (1923–2005, **Nobel Prize 2000**), Robert Noyce (1927–1990, no Nobel)

## Key Patents

- Kilby, J. US Patent 3,138,743 (1964) — integrated circuit
- Noyce, R. US Patent 2,981,877 (1961) — semiconductor device-and-lead structure

## Economic Value

Global semiconductor market: **\$600 billion/year** (WSTS 2023). Electronics, computing, and communications enabled by ICs: \$10–15T/year. The IC is arguably the single most economically important invention of the 20th century.

## Notes

WSTS *Semiconductor Market Forecast* 2023. McKinsey estimates cumulative IC-enabled economic value at >\$100T since 1960.

## What This Enables
⏎
- **[TECH] Personal Computer** — The microprocessor (an IC) is the central processing unit of every personal computer.
- **[TECH] Mobile Phones & Smartphones** — Smartphone SoCs (Apple A18, Snapdragon 8) are advanced ICs integrating CPU, GPU, modem, and AI accelerator on one die.
- **[TECH] Semiconductor Lasers & LEDs** — Laser driver ICs and photodetector arrays are essential components of every optical communications link.
⏎
# Parents

* [TECH] Transistor
* [TECH] Transistor