| 摘要 |
PURPOSE:To enable large-scale integration and to improve high yield by forming a source line by self-aligning simultaneously when forming a control gate. CONSTITUTION:A polysilicon film 14 and a field oxide film 12 for control gate formation are successively etched using a nitride film 15 and a resist 16 as masks. The nitride film 15 is etched, the polysilicon film 14 is etched using a difference in an etching rate of silicon and polysilicon with a mask of the resist 16, and finally the nitride film 15 and the resist 16 are removed. That is, an edge of the nitride film 15 is located under a word line, and thus only a part of the field oxide film where a source line is formed is etched upon etching for the field oxide film 12 after the patterning of the word line. The scale of integration and yield can be improved in this way. |
