Effects of surface treatments on isolation currents in AlGaN/GaN high-electron-mobility transistors.

Interdevice isolation currents in mesa-isolated AlGaN/GaN high-electron-mobility transistors are found to exhibit thermally activated behavior, with an activation energy of ∼1.5 eV. This value is largely independent of surface cleaning processes or the type of passivation film (SiN[sub X], Sc[sub 2]O[sub 3], MgO) used to reduce the current collapse phenomena in the devices. However, the magnitude of the isolation current is a strong function of the surface treatment employed. The lowest isolation currents for conditions under which current collapse is mitigated are obtained using Sc[sub 2]O[sub 3] passivation layers. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]