Complementary GaAs SIS FET inverter using selective crystal regrowth technique by MBE
A first complementary GaAs semiconductor-insulator-semiconductor (SIS) FET inverter has been fabricated by constructing n-channel and p-channel GaAs SIS FET's on a single LEC GaAs substrate using MBE selective crystal regrowth technique. The fabricated inverter shows an inverter operation as a really low-power complementary inverter.
A GaAs gate heterojunction FET
A new semiconductor-insulator-semiconductor field-effect transistor has been fabricated. The device consists of a heavily doped n-type GaAs gate with undoped (Al,Ga)As as the gate insulator, on an undoped GaAs layer. This structure gives the device a natural threshold voltage near zero, well suited for low-voltage logic. The threshold voltage is, to first order, independent of Al mole fraction and thickness of the (Al,Ga)As layer. The layers were grown by MBE and devices fabricated using a self-aligned technique involving ion-implantation and rapid thermal annealing. A transconductance of 240 mS/mm and a field-effect mobility of about 100 000 cm2/V-s were achieved at 77 K.
Modulation‐doped field‐effect transistor based on a two‐dimensional hole gas
We report the successful operation of the first p‐type, modulation‐doped field‐effect transistor ( p‐MODFET). The channel consists of a two‐dimensional hole gas at a GaAs/(AlGa)As heterostructure interface. With a gate length of 2 μm and a source‐drain distance of 7 μm we achieve transconductances of 28 mS/mm at 77 K and 44 mS/mm at 4.2 K. This work represents the first demonstration of a p‐type transistor that is the complement of the conventional n‐MODFET.