Abstract: The invention shows a method of a surface treatment on a fluorine silicate glass film. At first a fluorine silicate glass layer is deposited on a semiconductor wafer. Partial fluorine ions in the fluorine silicate glass layer are in-situ removed to form a silicon oxide layer of a pre-determined thickness. Then, a photoresist layer is coated on the silicon oxide layer. After an exposing process, a pre-determined latent pattern is formed in the photoresist layer. Finally, after a developing process, the pre-determined latent pattern of the photoresist is removed so as to expose corresponding portions of the silicon oxide layer underneath the latent pattern of the photoresist layer. As a result, the present invention solves a problem that fluorine ions in the fluorine silicate glass layer 24 diffuse to a surface of the fluorine silicate glass layer 24 to combine with water to form hydrofluoric acid, that contaminates the photoresist and leads to reliability issues.