The invention discloses a super-junction-based AlGaN / GaN MIS-HEMT (
Metal-Insulator-
Semiconductor High-
Electron-Mobility
Transistor) high-
voltage device and a fabrication method thereof. The structure of the high-
voltage device comprises a substrate, a GaN buffer layer, an intrinsic GaN (or AlGaN) channel layer, an AlN isolating layer and an AlGaN
barrier layer sequentially from the bottom up, a source, a grid, a drain, a linear AlGaN layer, a grid-
source field plate, a P-type GaN (or InGaN) layer and a base are arranged on the AlGaN
barrier layer, and an insulating medium layer is also arranged between the grid and the AlGaN
barrier layer. The invention has the advantages that: when the device is switched on, the 2DEG (2-dimensional
electron gas) concentration of a first region, a second region and a fourth region increases, the resistance decreases, and thereby the purpose of decreasing the
on resistance of the device is achieved; when the device is switched off, the 2DEG of the first region is reduced, the 2DEG of the second region and a third region is the same as that when the device is switched on, the width of the
depletion region of the device is increased, and thereby the purpose of increasing the
breakdown voltage of the device is achieved; the grid-source filed plate ensures that the
electric field peak cannot appear at the boundary where the grid is close to the source, thus increasing the
breakdown voltage; an insulated grid structure prevents grid leakage current, and thereby the performance of the device is enhanced.