Effects of heating ramp rates on the characteristics of AI implanted 4H-SiC junctions

The role of the heating rate in the postimplantation annealing process of SiC was investigated. Structural and electrical properties of an Al+ implanted junction in n-type 4H-SiC were studied for a 30 min annealing at 1600 degrees C in argon atmosphere and changing the heating rate between 7 and 40 degrees C/s. With the increasing of the heating rate the surface roughness increases, but the electrical performance of the devices improves. In particular, the faster ramp-up rate reduces the sheet resistance of the implanted layer of about 40% with respect to the slowest process and significantly reduces the leakage current of the diodes.