In this work, ElectroStatic Discharge (ESD) tests are performed on SiC MESFETs in order to understand their physical behavior and failure mechanisms during such stresses. The purpose is to point out advantages and drawbacks of this technology, paying special attention to aspects related to its possible commercialization and reliability. Three MESFETs designed to be integrated as a driver in monlithic SiC systems, featuring some ESD internal protection are investigated. Different configurations on ohmic and Schottky contacts are analyzed. Lock-in thermography is carried out for the physical failure location. With TCAD Sentaurus simulation, it allows to determine the nature of the defects on the damaged areas. Hypothesis on the failure mechanism as SiO 2 breakdown or SiC sublimation are presented. Solutions to increase the ESD robustness such as a Zener diode integration or the use of Al2O3 dielectric for passivation are therefore proposed in this article.