Fast particles generated by laser-plasma interactions can be used in many applications, from manufacturing to medicine and even for the initiation of tabletop nuclear reactions. Energetic proton generation by the interaction of an ultra-short high intensity laser pulse with a plasma has been demonstrated in recent theoretical and experimental papers, with maximum proton energies of up to 0.5 GeV having been observed. In this paper, particle-in-cell (PIC) simulations of fast particles produced by a short laser pulse of duration of 40 fs and intensity 10²⁰W/cm² interacting with a foil target are performed. The absorbed laser energy is transferred to fast electron, which interact with the foil and are partially ejected from the foil surfaces. These electrons produce an electric field that causes an proton beam to be emmited from the foil rear surface. Three kinds of target which are slab target, target with triangle cavity and target with circle cavity are considered. Effect of plasma foil target geometry on achievable energy of fast protons generated by an intense ultra-short laser pulse are analyzed.