GaAs structures with a gate dielectric based on aluminum-oxide layers

Different types of dielectrics obtained by low-temperature electron-beam sputtering are studied; these dielectrics include Al$_{2}$O$_{3}$ layers and Al$_{2}$O$_{3}$/SiO$_{2}$/Al$_{2}$O$_{3}$ three-layer compositions. The dependence of the electrical strength of Al$_{2}$O$_{3}$ layers on their thickness is determined. It is established that formation of the three-layer dielectric Al$_{2}$O$_{3}$/SiO$_{2}$/Al$_{2}$O$_{3}$ makes it possible to increase the range of operating voltages up to 60 V for structures with a gate electrode. It is shown that it is possible to control the density of charge carriers (holes) in the two-dimensional conduction channel of GaAs structures by changing the gate voltage when the Al$_{2}$O$_{3}$/SiO$_{2}$/Al$_{2}$O$_{3}$ structure is used as a gate dielectric.