Patent ID: 7314797

Claim:
A manufacturing method of a semiconductor device equipped with a non-volatile memory and a transistor, comprising: a step (A) wherein a field oxide film for unit separation is formed on the surface of a semiconductor substrate, and an active region surrounded by the field oxide film is formed, and a gate oxide film for the transistor is formed on the surface of the active region, a step (B) wherein a poly silicon film is formed all over the surface of the semiconductor substrate, a control gate is formed on the field oxide film at a memory unit region, and a gate electrode for the transistor is formed on the gate oxide film for the transistor by patterning the poly silicon film, a step (C) wherein an inter-layer silicon oxide film is formed on the surface of the control gate and the surface of the gate electrode for the transistor by a heat oxidization process, a step (D) wherein a gate oxide film for the non-volatile memory is formed on the surface of an active region of a memory unit region by a heat oxidization process after selectively removing the silicon oxide film on the surface of the active region of the memory unit region, and a step (E) wherein a poly silicon film is formed all over the surface of the semiconductor substrate, and a floating gate is formed on the inter-layer silicon oxide film at the memory unit region, the field oxide film, and the gate oxide film for the non-volatile memory by patterning the poly silicon film.