p-Channel MODFET's using GaAlAs/GaAs two-dimensional hole gas

Concepts

SemiconductorsHall MobilitiesElectrical EngineeringSemiconductor TechnologyEngineeringWide-bandgap SemiconductorRf SemiconductorSemiconductor DeviceNanoelectronicsElectronic EngineeringApplied PhysicsP-channel ModfetMicroelectronicsQuantum EngineeringGaalas/gaas System

Abstract

p-channel MODFET's were fabricated in the GaAlAs/GaAs system and the properties of the hole gas system tested to ascertain its suitability for complementary logic. The Hall mobilities on a Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">.5</inf> Al <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">.5</inf> As/GaAs modulation-doped hole gas structure were measured to be 3650 cm 2 V -1 s -1 and 54000 cm 2 V -1 s -1 with sheet carrier concentration of 1 × 10 12 cm -2 and 7.76 × 10 11 cm -2 at 77 and 4.2 K, respectively. The measured transconductances of 1.5-µm gate-length MODFET's on this structure were measured to lie in the range of 28-35 mS.mm -1 at 77 K. The field mobility measured on long gate-length MODFET's was approximately 3200 cm 2 V -1 s -1 at 77 K. Using test structures for measuring current voltage characteristic in the hole-gas system, low field drift mobility was measured to be 3000 cm 2 V -1 s -1 and velocities of 3 5 × 10 6 cm.s -1 were measured at electric fields of 3-4 kV.cm -1 at 77 K. The Schottky barriers showed low leakage and a barrier height of 0.7 to 0.8 eV. Calculations indicate that transconductances of approximately 100 mS.mm -1 should be achievable in this system for similar gate lengths.

References

Temperature dependence of the mobility of two-dimensional hole systems in modulation-doped GaAs-(AlGa)As

H. L. Störmer, A. C. Gossard, W. Wiegmann et al. · Applied Physics Letters · 1984 · 88 citations

Wide-bandgap Semiconductor, Optical Materials, Engineering +18