Lawrence Berkeley National Laboratory

Silicon carbide Low Gain Avalanche Detectors (4H-SiC LGADs), exhibiting an ultra-fast time response and excellent time resolution, are reported. Via TCAD simulations, the use of field plates is proposed to suppress the high electric field caused by the negative bevel-etched angle. Experimental measurements confirm that the field plate significantly increases the breakdown voltage. Gain and time resolution are measured by using the ultraviolet transient current technique (UV-TCT), showing that 4H-SiC LGADs possess excellent timing performance, with a time resolution better than 35 ps in response to an injected laser signal tuned to represent a single minimum ionizing particle (MIP) at room temperature. Additionally, the gain suppression effect is observed in the 4H-SiC LGAD for the first time.