transistorn

A transistor is a semiconductor device used to amplify or switch electronic signals. It consists of a small chip of semiconductor material, usually silicon or germanium, with three regions called the emitter, base, and collector. The device works by controlling current flow through the base, which in turn regulates a larger current between emitter and collector. Transistors discovered in 1947 by John Bardeen and Walter Brattain at Bell Labs marked the transition from vacuum tubes to solid‑state electronics.

There are two primary families of transistors. Bipolar junction transistors (BJTs) use both electrons and holes for conduction and were the first type widely adopted. Field‑effect transistors (FETs), including metal‑oxide‑semiconductor FETs (MOSFETs), control current with an electric field and are far more suitable for integrated circuit technology. Many variants, such as junction FETs (JFETs), insulated‑gate FETs (IGFETs), and heterojunction transistors, exist to meet specific performance requirements.

Transistors underpin modern digital computers, mobile phones, and a myriad of analog devices. In digital logic, complementary metal‑oxide‑semiconductor (CMOS) technology—producing both N‑channel and P‑channel MOSFETs on the same chip—provides high density, low power consumption, and fast switching. Analog applications include amplifiers, oscillators, and voltage regulators. The transistor’s ability to act as a controllable switch also made it essential for early radio, radar, and military systems.

Manufacturing a transistor requires carefully doped layers of semiconductor material, lithographic patterning, ion implantation, and metal contacts. Advances in the 1970s and 1980s, such as the introduction of planar technology and shallow trench isolation, allowed billions of transistors to be integrated on a single chip. Today, the International Technology Roadmap for Semiconductors continues to guide the scaling of transistor dimensions, transistor count, and power efficiency in pursuit of ever higher performance.

The transistor’s invention is widely regarded as a cornerstone of the Information Age, vastly expanding the scope and speed of processing data and shaping contemporary society.