Improvements in electrostatic channel control allow FinFETs and trigate FETs to extend Moore's law down to gate lengths of 15–20nm. Further scaling may require the better control that is provided by multigate devices. Using multigate FET architectures, gate length scaling down to 5 and 3 nm has been demonstrated experimentally and theoretically, respectively. At these dimensions, quantum confinement begins to appear and new effects such as drain current oscillations and tunneling through soft barriers can be observed. FET to SET and metal-semiconductor transitions resulting from quantum confinement present opportunities for new types of devices.