This paper reports research on deep etching of silicon carbide (SiC) to achieve isolated deep trenches in the same thick SiC substrates. This paper combines both plasma etching and electrochemical etching on p-type SiC above n-type SiC layers. Uniform and smooth plasma etched surfaces of SiC were obtained upon using Ni masks with significant thicknesses deposed by electroplating. This step allowed to etch unprotected SiC up to 30µm. Selective conductive electrochemical etching allows to obtain a higher etched thickness of silicon carbide substrates. The p-type layer will be inert and act as a stop layer, whereas, the n-type layer will be corroded. Finally, this paper obtains deep etching reaching around 80 micrometers, which opens the perspectives to start fabrication of vertical power-integrated SiC devices.