The fabrication of a fully ion-implanted vertical p–i–n diode using high-purity semi-insulating 4H–SiC substrate has been demonstrated for the first time. The intrinsic region is the wafer itself with a thickness of 350 µm. The anode and cathode are obtained by doping the front and back wafer surfaces with implanted Al+ and P+ ions, respectively, with concentrations of about 10 20 cm− 3. The electrical activation of the implanted dopants is obtained by microwave heating the samples up to 2100 C for 30 s. At±100 V the on and off state current ratio is in the order of 10 4. Forward saturation current is five orders larger than it would be if controlled by the series resistance of the thick HPSI 4H–SiC intrinsic region.