| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a flash memory device which can solve problems in small process margin and mass production margin in the existing process, while completely stripping a fence of dielectric layer in a gate formation process in which a thickness of a second conductive film used as a floating gate is over 1500Å. SOLUTION: The manufacturing method includes a first step of forming a tunnel oxide layer and a first conductive layer on a semiconductor substrate, and then performing a shallow trench isolation process to form an isolation layer that defines a first region and a second region; a second step of forming a second conductive layer on the entire structure, and then patterning the second conductive film and the first conductive firm to form a floating gate pattern; a third step of forming a dielectric layer, a third conductive layer, a fourth conductive layer, and a hard mask layer on the entire structure, and then patterning the hard mask layer; and a fourth step of etching from the fourth conductive film to the first conductive film in a single etch apparatus using the hard mask film as a mask, thus forming a control gate and a floating gate. COPYRIGHT: (C)2005,JPO&NCIPI
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