CURRENT-VOLTAGE CHARACTERISTIC COLLAPSE IN ALGAN GAN HETEROSTRUCTURE INSULATED GATE FIELD-EFFECT TRANSISTORS AT HIGH DRAIN BIAS/

The authors describe the current/voltage characteristic collapse under a high drain bias in AlGaN/GaN heterostructure insulated gate field e ffect transistors (HIGFETs) grown on sapphire substrates. These device s exhibit a low resistance state and a high resistance state, before a nd after the application of a high drain voltage, respectively. At roo m temperature, the high resistance state persists for several seconds. The device can also be returned into the low resistance state by expo sing it to optical radiation. Electron trapping in the gate insulator near the drain edge of the gate is a possible mechanism for this effec t, which is similar to what has been observed in AlGaAs/GaAs HFETs at cryogenic temperatures.