Building a transistor that sticks out of its parental chip lets many of its component atoms be deployed more usefully particularly those that constitute the channel and the gate.

ECONOMIST: Transistors

Only when all the masking and etching is complete is the sacrificial gate layer dissolved away, allowing the gates (and the insulation layers between the gate and channel of each transistor) to be filled in.

ECONOMIST: Transistors: A tall story | The

But it will do so on conventional, cheap silicon wafers without the need for the modified wafers or ultra-thin channels required by the SOI consortium, a trick it accomplishes by adding a second gate beneath the channel.

ECONOMIST: Transistors

The greater the gate length, the slower the transistor, since electrons passing through the channel in the transistor (which is the same length as the gate) have further to travel.

ECONOMIST: Transistors: A tall story | The

Applying a voltage to the gate determines whether or not current can flow through the channel.

ECONOMIST: Transistors: A tall story | The

The idea is to make the channel as thin as possible, allowing the electric field generated by the gate to penetrate the entire thing, thus improving the control that the gate is able to exert.

ECONOMIST: Transistors

By sticking the channel into the air and surrounding it on three sides with the atoms of the gate, you increase the surface area of the gate.

ECONOMIST: Transistors