Fabrication of AlxGa1-xN/GaN nanowires for metal oxide semiconductor field effect transistor by focus ion beam
We have grown the high quality AlGaN/GaN heterostructure by plasma-assisted molecular beam epitaxy. We obtained the mobility of two-dimensional electron gas of the AlGaN/GaN is 9300 cm2/Vs and carrier concentration is 7.9¡Ñ1012 cm-2 by conventional van der Pauw Hall measurement at 77K. The samples made of the AlGaN/GaN heterostructure were patterned to Hall bar geometry with a width of 20£gm by conventional photolithography. After the photolithography, the nanowire was fabricated by the process of focus ion beam (FIB), and the widths of nanowire were reduced to 900 nm, 500 nm, 300 nm, 200nm, 100 nm, 80 nm and 50 nm respectively. The SiO2 layer and Al electrode were deposed on the samples to form nanowired MOSFETs. We have studied the leakage current measurement on the AlGaN/GaN nanowired MOSFETs at 300K. On the 100 nm and 200 nm width of nanowires, we did not observe the leakage current for the gate voltage work range from -2.5 to 3.0 V and from -0.5 to 0.5 V respectively.
Advisor:Jih-Chen Chiang; Ikai Lo; Ming-Kwei Lee
School:National Sun Yat-Sen University
School Location:China - Taiwan
Source Type:Master's Thesis
Keywords:focus ion beam nanowire metal oxide semiconductor field effect transistor
Date of Publication:07/16/2008