Improved interface properties of GaN metal-oxide-semiconductor device with non-polar plane and AlN passivation layer

Utilizing a non-polar plane substrate and an ultra-thinAlNpassivation layer results in significantly improvedinterfaceproperties of aGaN metal-oxide-semiconductor (MOS) device. After depositing an Al2O3 gatedielectric layer onGaN substrates with polar c-plane and non-polar m-plane surfaces, it is found that the devices on the non-polar surface show much betterinterfaceproperties than those on the polar surface. To further improve theinterfaceproperties, an amorphous ultra-thinAlN layer is deposited on the substrate before the Al2O3 deposition. Theinterfaceproperties of both devices on the c-plane and m-plane are dramatically improved by theAlNpassivation layer. Theinterface trap density of the Al/Al2O3/AlN/GaNMOS capacitor on the non-polar surface is reduced by two orders of magnitude compared to that on the polar surface.

Source: Applied Physics Letters - December 5, 2016 Category: Physics Authors: Xian Wu, Renrong Liang, Lei Guo, Lei Liu, Lei Xiao, Shanshan Shen, Jun Xu and Jing Wang Source Type: research