Transistors - 2D and 3D
What do transistors do?
Transistors are the building blocks of microprocessors, which are the ‘brains' or computational devices inside PCs, laptops, smartphones and pretty much all modern electronic devices.
A transistor is essentially an automated switch that can store information as either a ‘1' or a ‘0', depending on whether the switch is on — letting electric current through — or off.
The wiring of several transistors together creates a device called a logic gate, which takes these ones and zeros and performs basic calculations with them. Home computers available today contain billions of transistors wired into logic gates, and have huge processing power as a result.
What's the difference between a 2-D and a 3-D transistor?
Transistors are usually made from silicon, which is a semiconductor — a material that can behave as both an electrical conductor and an insulator. They consist of a straight channel connecting a source to a drain, interrupted half way by a wide gate. The gate is what makes the transistor a switch: apply the right voltage and a conductive pathway known as an inversion layer forms, allowing current to flow from the source to the drain. In this instance, the transistor is on; without the inversion layer, no current flows and the transistor is off. All transistors mass-produced during the past 50 years or so have been 2-D. This means that the source, the drain and the channel connecting them all lie flat on the same plane.
In Intel's 3-D transistors, on the other hand, the channel protrudes from the surface in a ridge or ‘fin'. The result is that it has not one, but three sides in contact with the overlapping gate — thus its name ‘Tri-Gate.'