Performance Enhancement of Normally-Off Plasma-Assisted Atomic Layer Deposited Al2O3/GaN Metal-Oxide-Semiconductor Field-Effect Transistor with Postdeposition Annealing

作者：Ha Jong Bong^*; Kim Dong Seok; Im Ki Sik; Kim Ki Won; Kang Hee Sung; Park Ki Yeol; Lee Jung Hee

来源：Japanese Journal of Applied Physics, 2010, 49(12): 126501.

DOI：10.1143/JJAP.49.126501

A normally-off GaN-based metal-oxide-semiconductor field effect transistor (MOSFET) was fabricated using the Al0.3Ga0.7N/GaN heterostructure with a two-dimensional electron gas (2DEG) density of similar to 1 x 10(14) cm(-2) grown on a silicon substrate. The AlGaN layer in the gate region was fully recessed and the whole surface of the device was covered with a high-quality plasma-assisted atomic-layer-deposited (PAALD) Al2O3 layer, which plays the role of not only a gate insulator in the recessed gate region, but also a surface passivation layer in the ungated region between the source and the drain. The fabricated Al2O3/GaN MOSFET exhibited excellent device properties, such as a threshold voltage of 1.1 V extrapolated in the linear region at a drain voltage of 0.1 V, maximum drain current of 353mA/mm, field-effect mobility of 225 cm(2).V-1.s(-1), and on-resistance of 9.7 Omega.mm, which are among the best values ever reported for GaN MOSFETs fabricated on silicon substrates.

• 出版日期2010