Electrical Characterization of Al Implanted 4H-SiC Layers by Four Point Probe and Scanning Capacitance Microscopy

We studied the evolution of the electrical activation with annealing temperature and time in 4H-SiC implanted with Al ions at room temperature (RT). An accurate comparison between the electrical activation data obtained by FPP and SCM was carried out. The dependence of the electrically active profiles on annealing time was studied during isothermal (Tann=1600 °C) annealings for times ranging from 0 (spike anneal) to 30 min. By performing isochronal (t=30 min) processes at temperatures from 1550 to 1650 °C, the effect of the annealing temperature on the net doping concentration profiles was studied. Moreover, the activation energy (6.30.3 eV) associated to the process was extracted from the Arrhenius plot of the net active dose. Finally, the effect of the different thermal budgets on the roughening of the Al implanted 4H-SiC surface was also investigated in details by atomic force microscopy.