Controllable Phosphorus Doped Graphene Field Effect Transistor Using Phospho-Silicate Glass Films

Abstract

Wide-range controllable n-doping process of graphene on phosphosilicate glass(PSG) insulating substrate was demonstrated by adjusting the thermal process condition. This was achieved by two-step annealing process consisting of the first dopant out-diffusion and second activation steps. The doping control was accomplished by adjusting the concentration of the out-diffused P2O5 molecules from the PSG films. The increased amount of P2O5 molecules at the PSG surface and the smoothen surface through the annealing are predicted to strengthen the dipole moment and consequently the degree of n-doping. The feasibility of the n-doping process for graphene-based electronic devices was successfully demonstrated in this paper by fabricating a MOS capacitor with n-channel FETs on annealed graphene.