The transistors will appear in Intel’s new “Ivy Bridge” microprocessor, which will be made using a 22nm manufacturing process and begin shipping later this year. Intel’s processor is the first make the jump from 32nm to 22nm, continuing the decades-long race to keep boosting the number of transistors that can be packed into the same amount of space.
The switch to 3D addresses some fundamental problems that have been plaguing transistors as their feature size has shrunk. Transistors have long been two-dimensional affairs, with a source and a drain separated by a channel along which electrons flow. The only components that sit above the plane are the gate, which turns on and off the flow of electrons, and a thin, insulating layer sandwiched between the gate and the channel.
But as engineers have made transistors smaller and smaller, the distance from the source to the drain has gotten so short that electrons can leak through the lower part of the channel, where the gate’s influence is weakest, wasting power. To solve the leakage problem, transistor designers have been eyeing three-dimensional designs in which electrons have no place to go that isn’t controlled by the gate. (via Intel Transistors Enter the Third Dimension – IEEE Spectrum)