P형 in-situ 도핑 폴리실리콘 막질에 관한 연구

Study on P-type in-situ doped Polysilicon Films

This paper reports physical properties of in situ boron doped silicon films made from boron source gas and silane ($SiH_4$) gas in a conventional low-pressure chemical vapor deposition vertical furnace. If the p-type polysilicon is formed by boron implantation into undoped polysilicon, the plasma nitridation (PN) process is added on the oxide in order to suppress boron penetration that can be caused during the thermal treatments used in fabrication. In-situ boron doped polysilicon deposition can complete p-type polysilicon film with only one deposition process and need not the PN process, because there is not interdiffusion of dopant at the intermediate temperatures of the subsequent steps. Since in-situ boron doped polysilicon films have higher work function than that of n-type polysilicon and they are compatible with the underlying oxide, they may be promising materials for improving memory cell characteristics if we make its profit of these physical properties.