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ABSTRACT: High-performance enhancement-mode (E-mode) AlGaN/GaN metal-insulator-semiconductor HEMTs (MISHEMTs) were realized by using fluorinated Al<sub>2</sub>O<sub>3</sub> thin films as gate dielectrics. The depth profile of Fluoride atoms determined by X-ray photoelectron spectroscopy showed that the fluorine (F) ions were incorporated into the surface (approximately 2 nm) of the Al<sub>2</sub>O<sub>3</sub> gate dielectrics. With proper amount of F-ion incorporation, the threshold voltage of MISHEMTs shifted from - 4.8 to 0.11 V, converting depletion-mode (D-mode) MISHEMTs to E-mode ones. The E-mode MISHEMTs exhibited high performances including a high transconductance value of 153 mS/mm and a large saturated drain-current value I <sub>ds</sub> of 547 mA/mm. This paves a new way to fabricate E-mode AlGaN/GaN MISHEMTs and allows the monolithic integration of E/D-mode MISHEMTs for analog integrated circuits.
IEEE Electron Device Letters 11/2011; · 2.79 Impact Factor