Low ON-resistance and high current GaN Vertical Electron Transistors with buried p-GaN layers

Current Aperture Vertical Electron Transistors (CAVETs) benefit from the high electron mobility of the 2-dimensional electron gas (2-DEG) in the lateral direction and the better field distribution of the vertical geometry. Current flows laterally in the 2-DEG at the AlGaN/GaN heterojunction and is directed vertically down to the drain, through the aperture (Fig.1). A current blocking layer (CBL) is used to define the low resistance aperture. In this work, we use conductive Mg-doped MOCVD p-GaN as the CBL, hence blocking the current flow by the use of a reverse biased p-n junction as opposed to using insulating layers[1,2].