An Efficient 4H-SiC Photodiode for UV Sensing Applications
Mohamed L. Megherbi, H. Bencherif, L. Dehimi, Elisa D. Mallemace, Sandro Rao, F. Pezzimenti, Francesco G. Della Corte
Abstract
In this paper, we report experimental findings on a 4H-SiC-based p-i-n photodiode. The fabricated device has a p-type region formed by ion-implantation of aluminum (Al) in a nitrogen doped n-type layer. The dark reverse current density reaches 38.6 nA/cm2 at −10 V, while the photocurrent density rises to 6.36 µA/cm2 at the same bias under λ = 315 nm ultraviolet (UV) radiation with an incident optical power density of 29.83 μW/cm2. At the wavelength of λ = 285 nm, the responsivity is maximum, 0.168 A/W at 0 V, and 0.204 A/W at −30 V, leading to an external quantum efficiency of 72.7 and 88.3%, respectively. Moreover, the long-term stability of the photodiode performances has been examined after exposing the device under test to several cycles of thermal stress, from 150 up to 350 °C and vice versa. The achieved results prove that the examined high-efficiency UV photodiode also has a stable responsivity if subjected to high temperature variations. The proposed device is fully compatible with the conventional production process of 4H-SiC components.