Barrier enhancement of Ge MSM IR photodetector with Ge layer optimization

Abstract

Germanium thin films were deposited on n-type Silicon substrates with three different sputter power by using DC magnetron sputtering system at room temperature. The structural and morphological properties of the samples have been obtained by means of X-ray diffraction and atomic force microscopy measurements. Then, Germanium metal-semiconductor-metal infrared photodetectors were fabricated on these structures. The carrier recombination lifetime and the diffusion length of the devices were also calculated by using the carrier density and mobility data was obtained from the room temperature Hall Effect measurements. The dark current–voltage measurements of devices were achieved at room temperature. The electrical parameters such as ideality factor, Schottky barrier height, saturation current and series resistance were extracted from dark current–voltage characteristics. Finally, it has been shown that the barrier enhancement of Ge MSM IR photodetector can be achieved by Ge layer optimization.