AN INALAS/INAS MODFET

We report what we believe is the first InAs modulation-doped field-effect transistor (MODFET) using an epitaxial heterostructure based entirely on arsenides. The heterostructure was grown by MBE on InP and contains a 30-angstrom InAs channel. An L(G) = 2-mu-m device displays well-behaved characteristics, showing sharp pinch-off (V(th) = -0.8 V) and small output conductance (5 mS/mm) at 300 K. The maximum transconductance is 170 mS/mm with a maximum drain current of 312 mA/mm. Strong channel quantization results in an unprecedented breakdown voltage of -9.6 V, a several-fold improvement over previous InAs MODFET's based on antimonides. Low-temperature magnetic field measurements show strong Shubnikov-de Haas oscillations which, over a certain range of gate voltage, strongly hint that the electron channel resides in the InAs layer.