Stacked atomically thin transistors cut static power in test circuits
Researchers built vertically stacked transistors from atomically thin semiconductors and measured very low static power in small logic circuits. A single peer-reviewed study used a crystalline insulating layer to improve the interface controlling current. The measurements concern individual devices and circuits, with fabrication yield and further integration still limiting the experimental platform.
Science··Evening
A cleaner transistor interface
Researchers built stacked transistors using atomically thin semiconductors and a crystalline layer that electrically insulates their control gates. A transistor regulates current; imperfections where the semiconductor meets its insulation can disturb that control. The single peer-reviewed study, published on November 11, used single-crystal titanium dioxide to reduce charge trapping compared with an amorphous insulating layer. Both complementary transistor types operated with better-matched electrical behaviour.[1]
Very low power at rest
The two transistor types were placed vertically rather than beside one another. Small inverter circuits, which reverse a logic signal, consumed 38 femtowatts of static power with a 0.25-volt supply and around one picowatt at one volt. Static power describes consumption while the circuit holds its state. Switching a circuit adds another energy demand, so these measurements concern a particular part of circuit operation.[1]
Working circuits and fabrication yield
Half of fifty fabricated complementary structures worked. Sixteen underwent detailed electrical characterization. The study therefore reports an experimental circuit platform with a substantial fabrication shortfall. Results for still smaller gate dimensions came from calculations and simulations. The measured devices and the simulated designs represent different stages of development, while defects, production yield and compatibility with later manufacturing steps remain engineering constraints.[1]
