Fabrication High-Temperature 4H-SiC Schottky UV Photodiodes by O2 Plasma Pre-Treatment Technology

In this letter, an ultrahigh-temperature 4H-SiC Schottky ultraviolet (UV) photodiode (PD) using oxygen plasma pre-treatment (OPT) technology has been successfully fabricated and characterized. The PD has a high Schottky barrier height (SBH) of 1.94 eV. It shows excellent tolerance to extreme temperature with a dark current of 2.7 x 10(-8) A at -25 V and 600 degrees C. Under UV illumination, a record operating temperature of 600 degrees C is realized for the first time (PDCR = 3.5 at 600 degrees C, -25 V). Of note, the fabricated PD exhibits high responsivity that increases with the operating temperature from 0.17 A/W at room temperature (RT) to 0.52 A/W at 600 degrees C, at -25 V and 275-nm. Moreover, an expeditious response time of ms level is also realized from RT to 600 degrees C. These results demonstrate that the proposed 4H-SiC Schottky PD is advantageous for high-temperature UV-related applications.