devicestransistors

Transistors are semiconductor devices that can amplify or switch electronic signals. They were developed in the 1940s and revolutionized electronics by replacing vacuum tubes. In modern devices, they are the fundamental building blocks of integrated circuits and discrete components alike. Transistors enable digital logic, signal processing, and power regulation, allowing complex functionality in a compact form. The two broad families are bipolar junction transistors, which control current using a base-emitter junction, and field-effect transistors, which control current with an electric field applied to a gate.

Most transistors used in devices today are metal-oxide-semiconductor field-effect transistors (MOSFETs), fabricated on silicon using planar processes. In integrated circuits, huge numbers of transistors are interconnected to implement logic gates, memory cells, and analog blocks. Performance characteristics include gain, transconductance, threshold voltage, leakage, switching speed, and on-resistance. Transistor scaling, guided by Moore's law, has driven increases in speed and reductions in size and power consumption, though it raises challenges in heat, variability, and manufacturing cost. Packaging formats range from discrete packages to very large-scale integration in silicon ICs.