A study has been made of electric conductivity and structure of Ar ion implanted diamonds depending on the target temperature during Ar implantation. A 150 keV Ar implantation into natural la-type diamonds held at the temperatures ranging from -60 to 300°C was performed with doses of 2-6×10¹⁶ ions/cm². The sheet resistivity was measured by a four point probe method at room temperature. The sheet resistivity was varied depending on target temperatures by two or more orders of magnitude; The critical target temperature giving remarkable change in the resistivity was nearly equal to room temperature. Raman spectra showed that the surface structure is amorphous in the specimen implanted at the target temperature of -60°C and is disordered-graphite including amorphous zones in the one at the target temperature of 200°C.
It is concluded that the final target temperature plays an important role in forming the different structures in implanted diamonds to change the sheet resistivity. When we implant Ar-ions in 200°C-implanted diamonds at -60°C or in -60°C-implanted diamonds at 200°C, the sheet resistivity shows to be dependent on the final temperature at the final stage of ion implantation.