In this letter, the physical effects of the local surface thin thermal oxidation on the current transport in AlGaN/GaN heterostructures are reported. Current-voltage measurements performed on appropriate test patterns demonstrated that a selective oxidation process at 900 degrees C enables the suppression of the current flow through the two-dimensional electron gas. The electrical insulation was achieved even though structural analysis showed that the formed oxide did not reach the depth of the AlGaN/GaN heterointerface. The combination of capacitance-voltage measurements with depth-resolved scanning capacitance microscopy enabled to correlate the electrical results to the doping and the compositional stability of the material during oxidation. (c) 2008 American Institute of Physics.
Two-dimensional electron gas insulation by local surface thin thermal oxidation in AlGaN/GaN heterostructures
Roccaforte F;Giannazzo F;Bongiorno C;Raineri V
2008
Abstract
In this letter, the physical effects of the local surface thin thermal oxidation on the current transport in AlGaN/GaN heterostructures are reported. Current-voltage measurements performed on appropriate test patterns demonstrated that a selective oxidation process at 900 degrees C enables the suppression of the current flow through the two-dimensional electron gas. The electrical insulation was achieved even though structural analysis showed that the formed oxide did not reach the depth of the AlGaN/GaN heterointerface. The combination of capacitance-voltage measurements with depth-resolved scanning capacitance microscopy enabled to correlate the electrical results to the doping and the compositional stability of the material during oxidation. (c) 2008 American Institute of Physics.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
