Understanding the failure mechanisms is essential to ensure reliability for a new technology of semiconductors. Amongst various existing tools dedicated to silicon-based devices, there is no consensual method for silicon carbide (SiC) devices. This semiconductor offers very interesting properties for power electronics in comparison with Si, but these failures are different and need to be studied. This paper will compare different methods applied to failures, focusing on lock-in thermography and micro-Raman analysis. Three devices will be evaluated, a vertical diode, a lateral diode and a MESFET. A methodology will finally be recommended as a valuable and robust solution for failures mechanisms further studies.