Molecular beam epitaxy of modulation doped N-AlGaAs/(InAs/GaAs)/GaAs superlattices at thikness of InAs layers below and near threshold of nucleation quantum dots for high frequency applications

Modulation doped N-AlGaAs/GaAs/InAs/GaAs/InAs/GaAs-heterostructures with InAs-quantum dots have been grown and investigated. Their photoluminescence spectra and electrical transport properties both in low and high electric fields were studied. Using these structures, modulation doped FET’s have been fabricated and analyzed. It was demonstrated that the quantum dot FET’s present the new type of the hot electron devices, promising for high frequency applications

AlGaN/GaN-heterojunction FET with inverted 2DEG Channel

Novel heterojunction AlGaN/GaN-FET with inverted device channel is investigated.FET-heterostructures were grown by MBE on sapphire substrates. Devices were fabricated with 0,25 µ T-shaped gates,using electron beam lithography.Electron density profile under the device gate has demonstrated localization of electrons in very narrow nm-region (1A/mm,and good extrinsic transconductance gm ext ≅140mS/mm.DC - specific output power of HEMT was 2,0W/mm.Extrinsic cut off frequency f τ ext of HEMT,determined from transconductance gm and gate-source capacitance Cgs, was 20GHz.Its intrinsic value,f τ ext ,was found to be as high as 36GHz

High frequency devices and high speed integrated circuits technology, based on the A3B5-semiconductor compounds, in the republics of the former USSR

The present paper is devoted to a brief analysis of the present state and the prospects for the future of technology of the high frequency devices and high speed integrated circuits based on the A3B5 semiconductor compounds, including the A3B5-heterostructures, in the republics of the former USSR