Deep level transient spectroscopy of n-AlGaAs/GaAs high electron mobility transistors

Deep level transient spectroscopy has been used to characterise the traps found in MBE grown n-AlGaAs/GaAs HEMT's. In addition to DX centres two further traps common to different HEMT structures are reported. We have identified an electron trap (E= a 0•6 eV) distributed nonuniformly in the AlGaAs donor layer, and an interface state trap (E a =0•55 eV) located close to the two dimensional electron gas