  The 4H-SiC material exhibits good detection performance, but there are still
many problems like signal distortion and poor signal quality. The 4H-SiC low
gain avalanche detector (LGAD) has been fabricated for the first time to solve
these problems, which named SICAR (SIlicon CARbide). The results of electrical
characteristics and charge collection performance of the 4H-SiC LGAD are
reported. The influence of different metal thicknesses on the leakage current
of the device is studied.~By optimizing the fabrication process, the leakage
current of the detector is reduced by four orders of magnitude. The
experimental results confirm this 4H-SiC LGAD has an obvious gain structure,
the gain factor of the SICAR is reported to be about 2 at 150 V. The charge
collection efficiency (CCE) of the device was analyzed using $\alpha$ particle
incidence of 5.54 MeV, and the CCE is 90\% @100~V. This study provides a novel
4H-SiC LGAD radiation detector for application in the field of high energy
particle physics.
