Reconfigurable Ferroelectric Field-Effect Transistors with Single-Walled Carbon Nanotube Channels

 

The rapid development of the internet and artificial intelligence has accelerated data generation, imposing greater demands on data processing. To process data efficiently, it is necessary to reduce device dimensions and operating voltage, thereby lowering energy consumption.

However, with current field-effect transistor (FET) technology, such as silicon complementary metal-oxide-semiconductor (CMOS) transistors, these improvements have met with physical limitations: when transistors become too small, electrical control issues arise. More specifically, size reduction is hindered by effects associated with short channel length; while lowering the voltage below 1 V is constrained by the Boltzmann limit, which depends on the constant ratio between the interaction potential and the mean free path of charge carriers.

Considering these limitations, reconfigurable transistors—capable of changing their operation after fabrication—offer a promising alternative. A special case is reconfigurable FeFETs, which can operate as either p-type or n-type transistors as needed.

A research team from Korea, the U.S., and China developed this type of devices using highly aligned single-walled carbon nanotubes (SWCNTs) as semiconductor channels and an innovative ferroelectric material (aluminum–scandium nitride). These devices exhibit ambipolar carrier characteristics with high and well-balanced ON-state currents (~270 μA μm−1 at a drain voltage of 3 V) and ON/OFF ratios greater than 105, along with wide memory windows and excellent retention capability. Furthermore, they feature ternary memory capability (able to store -1, 0, or +1 instead of just 0 and 1). This means that more compact and efficient circuits can be built compared with those based on conventional silicon.

Further information in: Nature Communications