Annealing temperature dependence of the electrically active profiles and surface roughness in multiple Al implanted 4H-SiC

In the present work, we systematically studied the effect of the annealing temperature (from 1400 degrees C to 1650 degrees C) on the electrical activation of 4H-SiC implanted with multiple energy (from 40 to 550 keV) and medium dose (1x10(13) cm(-2)) Al ions. The evolution of the acceptor (N(A)) and compensating donor (N(D)) depth profiles was monitored by the combined use of scanning capacitance microscopy (SCM) and scanning spreading resistance microscopy (SSRM). We demonstrated that the electrical activation of the implanted layer with increasing annealing temperature is the result of the increase in the acceptor concentration and of the decrease in the N(D)/N(A) ratio. Atomic force microscopy (AFM) morphological analyses indicated that the surface quality is preserved even after the 1650 degrees C annealing process.