AlGaN/GaN Schottky Barrier Diodes Employing Diamond-like Carbon passivation

AlGaN/GaN Schottky Barrier Diodes (SBDs) employing the Diamond-like Carbon (DLC) passivation was proposed. The reverse blocking characteristics of the AlGaN/GaN SBD is degraded by the electron trapping effect through the surface trap states. In order to suppress the electron trapping effect and increase the breakdown voltage of AlGaN/GaN SBDs, the surface passivation or treatment should be performed. In this paper, we proposed the DLC film as passivation layer on AlGaN/GaN SBD which exhibits superb dielectric characteristics such as high resistivity, high critical electric field and low dielectric constant. We successfully increased the breakdown voltage of AlGaN/GaN SBDs from 204 V to 1422 V by performing the DLC passivation. The ideality factor was improved from 1.959 to 1.273. And, the Schottky Barrier height was increased from 0.67 eV to 0.8 eV after the DLC passivation. However, the forward current was degraded a little due to the intrinsic stress of the DLC film.