Material and electrical properties of titanium-based ohmic contacts on p-type 4H-SiC were investigated depending on the post-annealing and the metal covering conditions. Best results are obtained as 4×l0^(-4) ohm.㎠ for Co/Si/Ti metal structures aft...
Material and electrical properties of titanium-based ohmic contacts on p-type 4H-SiC were investigated depending on the post-annealing and the metal covering conditions. Best results are obtained as 4×l0^(-4) ohm.㎠ for Co/Si/Ti metal structures after a vacuum annealing at 850℃ for 60 sec. The contact resistance was measured by a transmission line technique, and the contact resistances were improved more than one order compared to Ti and Co/Ti contacts for the annealed samples at the same conditions. The Co layer is supposed to reduce the oxidation of Ti films, and the Si layer plays a role of diffusion barrier to the intermixing of Ti and Co atoms. which was considered as a major cause for the large contact resistance.