Abstract: Vanadium ion (V+) implantation at a high energy (2100keV) is successfully used to form semi-insulating layers in 4H-SiC.The fabrication processes and measurements of the implanted layer are reported in detail.The profile of the ion implantation is simulated with the Monte Carlo simulator TRIM.Test patterns on semi-insulating 4H-SiC samples are processed into a mesa structure,and resistivity measurements are conducted.The resistivities of V+-implanted layers are strongly dependent on the conduction type of the initial 4H-SiC samples,and they are about 1.6E10 and 7.6E6Ω·cm respectively for p- and n-type samples at room temperature.The resistivities of the as-implanted samples increase with increasing annealing temperature for both p- and n-type samples due to the introduction of compensating levels.However,they decrease slightly beyond 1700℃ due to the diffusion of vanadium.The temperature dependent resistivity behavior in V+-implanted n-type 4H-SiC indicates an activation energy of 0.78eV.

Key words: SiC, semi-insulating, vanadium ion implantation, annealing, activation energy