Paper in Nano Letters demonstrates beta-gallium oxide FinFETs and logic inverters operating reliably at 2 K, enabled by silicon-dopant impurity-band conduction.
Key Takeaways
KAUST team built two devices, a FinFET and a NOT gate inverter, from silicon-doped β-Ga2O3; both held performance at 2 K.
Conventional silicon and III-V semiconductors freeze out below ~100 K; β-Ga2O3 avoids this because electrons hop through an impurity band formed by silicon dopant atoms.
The ultrawide bandgap also lets the same material operate up to 500°C, covering the full temperature swing space probes encounter.
This is the first ultrawide-bandgap semiconductor used to build transistors and logic inverters at cryogenic temperatures, not just passive components.
Near-term target is a single-material cryogenic chip toolbox: RF transistors, photodetectors, and memory cells, reducing thermal management bulk in quantum computers and spacecraft.
