An InAlAs/InAs MODFET

The fabrication and testing of an InAs modulation-doped field-effect transistor (MODFET) using an epitaxial heterostructure based entirely on arsenides are discussed. The heterostructure was grown by molecular beam epitaxy (MBE) on InP and contains a 30 A InAs channel. An L/sub G/=2 mu m device displays well behaved characteristics, showing sharp pinch-off (V/sub 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 breakdown voltage of -9.6 V, a severalfold improvement over previous InAs MODFETs based on antimonides. Low-temperature magnetic field measurements show strong Shubnikov-de Haas oscillations from which the electron channel is confirmed to be the InAs layer.<
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