Hall mobility and carrier concentration versus temperature for type IIa natural insulating diamond doped with boron by ion implantation

A natural IIa diamond was implanted with boron ions at a substrate temperature of 80 K. Ohmic contacts (Mo/Au) were formed using a solid‐state reaction process. Van der Pauw resistivity/Hall measurements were taken as a function of temperature from room temperature to nearly 600 °C. Heating to approximately 350 °C was necessary to stabilize resistance values to over 3.4 MΩ/sq and 1.3 MΩ/sq for the unimplanted and implanted sides, respectively, indicating possible hydrogen incorporation into the diamond during annealing of the metallized sample in hydrogen. Comparison of the electrical properties of the implanted and unimplanted sides showed that the boron implant introduced electrically active acceptors.