| abstract |
The purpose of the present invention is to prevent the reliability of a semiconductor device from being lowered when two types of sidewalls having different widths are to be formed on a substrate because the gate electrodes are buried by the insulating film for sidewall formation. In order to achieve the above-mentioned purpose, the gate electrode G2 of the low-withstand voltage MISFETQ2 and the sidewall of the pattern including the control gate electrode CG and the memory gate electrode MG are formed into a sidewall shape through a silicon nitride film NT3. After removing the silicon oxide film OX4, the silicon oxide film OX4 next to the gate electrode G2 is removed, and then a silicon oxide film OX5 is formed on the semiconductor substrate SB and etched back. Thereby, a sidewall SW1 composed of a silicon nitride film NT3 and a silicon oxide film OX5 is formed beside the gate electrode G2, and a silicon nitride film NT3, a silicon oxide film OX4 and OX5 are formed beside the above pattern. The formed side wall SW2. |