Title :
Positive Shift in Threshold Voltage for Reactive-Ion- Sputtered Al2O3/AlInN/GaN MIS-HEMT
Author :
Dutta, Gourab ; Turuvekere, Sreenidhi ; Karumuri, Naveen ; DasGupta, Nandita ; Dasgupta, Avirup
Author_Institution :
Dept. of Electr. Eng., IIT Madras, Chennai, India
Abstract :
AlInN/GaN metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs) have been fabricated with reactive-ion-sputtered (RIS) Al2O3 as a gate dielectric. Significant reduction in the gate leakage current is achieved upon insertion of RIS-Al2O3. MIS-HEMTs also show better transconductance, drain characteristics, and ION/IOFF ratio. Most interestingly, a positive shift in threshold voltage is observed for MIS-HEMTs indicating the presence of net negative charge at oxide-semiconductor interface. The origin and stability of the negative charge at the interface is discussed in this letter.
Keywords :
III-V semiconductors; MIS devices; aluminium compounds; gallium compounds; high electron mobility transistors; indium compounds; leakage currents; sputter etching; wide band gap semiconductors; Al2O3; AlInN-GaN; AlInN-GaN MIS-HEMT; RIS Al2O3; gate dielectric; gate leakage current; metal-insulator-semiconductor high electron mobility transistors; net negative charge; oxide-semiconductor interfacepositive shift; reactive-ion-sputtered Al2O3; threshold voltage positive shift; Aluminum oxide; Capacitance-voltage characteristics; Dielectrics; Gallium nitride; HEMTs; Logic gates; Threshold voltage; Al₂O₃; Al2O3; AlInN/GaN; MIS-HEMT; interfacial negative charge; reactive ion sputtering; threshold voltage shift;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2014.2357837
