Entrapment and thermal stability of low energy Argon implanted into diamond studied by in-situ X-ray photoelectron spectroscopy and thermal programmed desorption

Abstract

The retention and thermal stability of Ar implanted into polycrystalline diamond surfaces with 700 and 5000 eV Ar ions, with high dose (HD) and low dose (LD) of 1016 and 1014 ions/cm2 at room temperature (RT) and 400 °C were investigated. Upon implantation at 400 °C, the thermal stability of the retained Ar is very high and can exceed 1000 °C, whereas, upon RT implantation at the same energy, it is below ∼800 °C. Ar entrapped in a local high crystalline diamond environment possesses a very high thermal stability compared to when it is entrapped in a graphite/amorphous local carbon environment. Ar thermal desorption occurs via diffusion between local defects, greatly enhanced between 600 and 700 °C. Implantation at 400 °C (at HD) results in two distinct regions: graphitic and highly crystalline diamond with low defect density due to dynamic annealing and direct desorption of Ar entrapped within the graphitic/damaged region during the implantation. Ar entrapped in a high crystalline diamond matrix is under higher compressive stress than in graphitic/amorphous carbon.