Interface-controlled gate of GaAs metal-semiconductor field-effect transistor

A two-step passivation using sulfidation and hydrogenation has been reported to improve the gate leakage current and breakdown voltage of the GaAs metal-semiconductor field-effect transistor (MESFET). The combination of S passivation and interfacial hydrogenation was applied to the gate line in the MESFET; leakage current was reduced over an order and breakdown voltage was improved to a maximum level of 14 V from 10 V. It was revealed that the improvement of device properties after this two-step treatment resulted from the suppression of defective states such as oxides and excess As at the interface of the gate junction. The evolution of their bonding states through the treatment was found to have a close relationship with the device parameters.