Electron mobility in bulk III-V semiconductors is about an order of magnitude higher than in silicon, which promises much faster nanometer-scale electronics in GaAs-based devices. However, fabrication of metal oxide – semiconductor field effect transistors (MOSFETs), the central element of modern electronics, with III-V semiconductors is hampered for years by the unresolved problem of the semiconductor to a metal-oxide interface. Exposure of the III–V surface to oxygen results in the appearance of the interfacial states that reduce the charge mobility and cause the ‘Fermi-level pinning’, which is an inability to modulate the electrostatic potential inside the semiconductor. Partial solutions were found; however, the problem remains acute. In this invention, we disclose the method of passivation and fabrication of heterogeneous structures comprising III-V semiconductors and metal oxide dielectrics with free of pinning high mobility interfaces. The heterogeneous structures are produced by a direct RF sputtering of the metal oxide material on the III-V semiconductor surface in the atmosphere containing argon and oxygen. The mobility of the passivated interfacial channel is enhanced by up to two orders of magnitude and approaches the intrinsic value of clean GaAs crystals.

Mobility of the original and passivated GaAs wafers