Method for forming a high-RI oxide film to reduce fluorine diffusion in HDP FSG process

摘要

A method for forming a high-RI dielectric liner layer to prevent out diffusion of fluorine substances in an intermetal dielectric (IMD) layer of an semiconductor device is provided. The method comprises following steps. First, a patterned conductive layer is deposited on a substrate. Then, a dielectric liner layer is formed by high density plasma enhanced chemical vapor deposition method or plasma enhanced chemical vapor deposition method. The dielectric liner layer is silicon dioxide and has a high-RI between about 1.5 to 1.8. Next, a fluorinated silicate glass layer is deposited on the dielectric liner layer. The high-RI dielectric liner layer is used to reduce out diffusion of fluorine substances in the fluorinated silicate glass layer. Last, it is proceeded a chemical mechanism polishing process to remove additional fluorinated silicate glass layer and the dielectric liner layer.