An extensive characterization work has demonstrated the diamond-graphite phase transition and an ohmic electrical behaviour for the contacts with a resistivity of the order of ≈ 10^-5 Ω.m. An experimental set-up dedicated to the laser writing technique on diamond has been developed in both hardware and software aspects and a protocol for the manufacturing of segmented graphitic contacts on diamond surface of large scale (cm2) has been implemented. The work at 元 was dedicated to the laser-induced diamond graphitization process in order to produce graphitic electrodes on intrinsic diamonds. The main aim was the manufacturing of ohmic contacts on diamond surface for detector and electronic device applications. This PhD work has been carried out in international cotutelle agreement between the University of Salento (元, Italy) and the University of Paris 13 (LSPM, France). Nanoscale evidences of amorphisation, lattice reconstruction and dopant activation are presented and discussed in this work. Crystalline reconstruction, evidenced by TEM data explains the related electric behaviour. Boron ion implantation was used to create ohmic contacts in two different diamond samples, treated with different annealing velocities. On the other hand, CL spectroscopy reveals how A-Band and free exciton emission peaks, which are quenched by B⁺ implantation, recover after annealing. Indeed, at 1600 ☌, sp²/sp³ ratio in implanted regions changes from 0.56 to 0.18 (0.15 value was measured before implantation).
Carbon-related peaks of EELS spectroscopy shows a nearly complete recovery of the diamond lattice after thermal treatment. In addition, TEM observations allowed localizing the boron spatial distribution. The present contribution evaluates by STEM-EELS and CL spectroscopy the amorphisation of diamond lattice under the B⁺ bombardment and its subsequent reconstruction after the thermal treatment. To obtain p-type doping of diamond through B ion implantation, thermal treatments are necessary to reconstruct the diamond lattice and to locate B atoms in substitutional lattice positions.
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