Title :
AlGaN/GaN MOSHEMTs With Liquid-Phase-Deposited
as Gate Dielectric
Author :
Wu, Tsu-Yi ; Lin, Shun-Kuan ; Sze, Po-Wen ; Huang, Jian-Jiun ; Chien, Wei-Chi ; Hu, Chih-Chun ; Tsai, Ming-Ji ; Wang, Yeong-Her
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
Abstract :
TiO2 films deposited on GaN layers at room temperature through a simple and low-cost liquid-phase deposition (LPD) method are investigated and served as gate dielectrics in AlGaN/GaN MOSHEMTs. The electrical characteristics of the MOS structure on n-doped GaN show that the leakage current is about 1.01times10-7 A/cm2 at 1 MV/cm and that the breakdown field is more than 6.5 MV/cm. The maximum drain current density of MOSHEMTs is higher than that of conventional HEMTs, and a wider gate voltage swing can also be observed. The maximum transconductance and threshold voltage almost maintain the same characteristics, even after inserting a dielectric layer between the gate metal and the 2DEG channel by using TiO2 as a gate dielectric. The gate leakage current density is significantly improved, and the bias stress measurement shows that current collapse is much suppressed for MOSHEMTs.
Keywords :
MOS integrated circuits; aluminium compounds; gallium compounds; high electron mobility transistors; titanium compounds; AlGaN-GaN; MOSHEMT; TiO2; gate dielectric; gate leakage current density; low-cost liquid-phase deposition; maximum transconductance; threshold voltage; Aluminum gallium nitride; Current density; Dielectric liquids; Electric breakdown; Electric variables; Gallium nitride; HEMTs; Leakage current; MODFETs; Temperature; AlGaN/GaN; GaN; MOSHEMT;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2009.2032745