Annealing condition optimization and electrical characterization of amorphous LaAlO3∕GaAs metal-oxide-semiconductor capacitors

The electrical properties of amorphous LaAlO3∕GaAs metal-oxide-semiconductor capacitors fabricated using molecular-beam deposition are investigated. The surface was protected during sample transfer between III-V and oxide molecular beam epitaxy chambers by a thick arsenic-capping layer. Amorphous LaAlO3 was deposited on c(4×4) and (2×4) reconstructed (100) GaAs surfaces. An annealing method, a low temperature-short time rapid thermal annealing (RTA) followed by a high temperature RTA, was developed, yielding extremely small hysteresis (∼30mV), frequency dispersion (∼60mV), and interfacial trap density (mid-1010eV−1cm−2).