Achievement of p-type doping in gallium nitride by beryllium implantation

For the first time, p-type doping through beryllium implantation in gallium nitride was achieved by using a new annealing process, in which the sample was first annealed in forming gas and then in pure nitrogen. The sheet concentration of the holes was estimated to be about 2 × 10¹³ cm^-2 from Hall measurements. The structures of the samples annealed under different conditions were analyzed using high resolution X-ray diffractometry and Rutherford back scattering. The results showed that the crystal structure of the implanted region was almost restored after annealing, except for possibly some point defects.