| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for simultaneously manufacturing a high voltage element and a low voltage element by nitriding oxynitrided films of different thicknesses after being formed in one oxidizing process, and forming a dual gate insulating film whose dielectric constant is increased. SOLUTION: After a semiconductor substrate is settled in high voltage and low voltage element regions, a screen oxide film is formed all over the substrate. Nitrogen ions are implanted only into the semiconductor substrate in the low voltage element region, and then rapid thermal treatment is performed. After the screen oxide film is removed, oxidization is performed in a gas atmosphere containing nitrogen and oxygen to form first and second oxynitrided films of different thicknesses on the semiconductor substrate in the high voltage and low voltage element regions. Then, they are rapidly nitrided to form a dual gate insulation film comprising third and fourth oxynitrided films. A polysilicon film is formed all over the film, and then the polysilicon film and specified regions of the third and fourth oxynitrided films are etched, respectively, to form first and second gate electrodes. COPYRIGHT: (C)2004,JPO
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