in this paper we propose and simulate a new heterostructure mesfet, called δ-doped ldd hmesfet. to improve carrier velocity in vicinity of the source in channel of gaas mesfet, one can replace source with alxga 1-x as. by increasing al content, discontinuity of hetero-interface could be increased. therefore, the velocity increases in the low field. however, increasing al mole fraction in excess...

Fermi-level pinning phenomena due to DX centers in AlGaAs/GaAs HEMT’s are analyzed using two-dimensional numerical simulation based on a drift-diffusion model. A DX center model is introduced assuming Fermi-Dirac statistics for ionized donor density with the aluminum mole fraction dependence of the deep-donor energy level. The calculated results reveal that the decrease in transconductance of A...

Dx centers have been investigated using deep level transient

We demonstrate that x-ray irradiation can be used to induce an insulator–metal transition in Si-doped Al0.35Ga0.65As, a semiconductor with DX centers. The excitation mechanism of the DX centers into their shallow donor state was revealed by studying the photoconductance along with fluorescence. The photoconductance as a function of incident x-ray energy exhibits an edge both at the Ga and As K ...