In this study, the undoped amorphous layers and phosphorus doped amorphous layers are fabricated using LPCVD at 531$^{circ}C$ with SiH$_4$ gas or at same temperature with PH$_3$ gas during deposition, respectively. The thickness of deposited amorphous layer from this experiments was 5000 ${AA}$. In this experiments, undoped amorphous layers are deposited with SiH$_4$and Si$_2$H$\_$6/ gas in a low pressure reactor using LPCVD. These amorphous layers can be doped for poly-silicon by phosphorus ion implantation. The experiments of this study are carried out by phosphorus ion implantation with energy 40 keV into P doped and undoped amorphous silicon layers. The distribution of phosphorus profiles are measured by SIMS(Cameca 6f). Recoiling effects and two dimensional profiles are also explained by comparisions of experimental and simulated data. Finally range moments of SIMS profiles are calculated and compared with simulation results.