Ultra Fast High Temperature Microwave Annealing of Ion Implanted Large Bandgap Semiconductors

In this work, the surface, lattice and electrical properties of implanted 4H-SiC, GaN and ZnO, annealed by a novel ultra-fast microwave heating method, are compared to that of conventional annealing methods. In this new method, amplified and variable frequency microwaves from a signal generator are directly coupled to the semiconductor sample through a microwave head. Since, the microwaves are only absorbed by the sample, without heating of the ambient, ultra-high heating (> 2000 degrees C/s) and cooling rates and very high (2100 degrees C) annealing temperatures can be reached. For Al and P species implants into 4H-SiC, record low resistivity values were achieved with a lattice quality better than that of the virgin crystal. This annealing method improved the lattice quality of un-implanted region below the surface implanted region as well. Improved material characteristics were also obtained for GaN and ZnO.