Experimental analysis and 2D-simulation of C-V characteristics in Ag/poly(Si)/ITO/glass Schottky diode

Abstract A silver contact with polysilicon fabricated on glass substrates was investigated both experimentally and theoretically by means of measured and 2D-simulated C – V characteristics. The in situ phosphorus-doped polysilicon layer is grown by a low-pressure chemical vapor deposition (LPCVD) technique and crystallized in a vacuum by thermal annealing. The measured C −2 – V characteristics of the Schottky contact at two frequencies reveals a linear behaviour at the 10 kHz curve and a distinct non-linear behaviour at the 300 kHz one. Extraction of the frequency independent capacitance by the Kevin method allows the determination of the values of doping concentration ( N D  = 5 × 10 18  cm −3 ) and Schottky barrier height ( ϕ b  = 0.65 eV). The 2D-numerical simulation code of the Schottky contact C – V characteristics is also developed by considering that the inter-granular traps density N T is localized in the grain boundaries. The effects of the film doping concentration and the trap states density are investigated.