Ultrathin AlN/GaN heterostructure field-effect transistors with deposition of Si atoms on AlN barrier surface

作者：Onojima Norio^*; Hirose Nobumitsu; Mimura Takashi; Matsui Toshiaki

来源：Applied Physics Letters, 2008, 93(22): 223501.

DOI：10.1063/1.3036007

• aluminium compounds
• electron beam deposition
• elemental semiconductors
• field effect transistors
• gallium compounds
• III-V semiconductors
• ohmic contacts
• semiconductor heterojunctions
• silicon
• two-dimensional electron gas
• vacuum deposition

We deposited Si atoms on the AlN barrier surface of an ultrathin AlN/GaN heterostructure field-effect transistor (HFET). This induced a remarkable change in the electrical properties of the two-dimensional electron gas. A 2-nm-thick Si layer reduced the sheet resistance of an AlN/GaN HFET (AlN barrier, 2 nm) from 60 356 to 388 Omega/sq. The effect on the Ohmic contact was also significant: the presence of an undermost layer of Si atoms under Ohmic contacts produced a low specific contact resistance of 1.7x10(-6) Omega cm(2). A 50-nm-gate AlN/GaN HFET with a Si layer exhibited excellent device characteristics with a current-gain cutoff frequency of 106 GHz.

• 出版日期2008-12-1