| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a semiconductor device which comprises a nonvolatile memory cell including a memory transistor having a floating gate but not having a control gate and including a select transistor, comprises a peripheral circuit transistor, and has an improved charge holding characteristic of the memory transistor. <P>SOLUTION: The semiconductor device comprises a memory transistor having a memory gate oxide film 15 on a semiconductor substrate 2, and a floating gate 17 formed on the memory gate oxide film 15; a nonvolatile memory cell including a select transistor having a select gate oxide film 11 formed on the semiconductor substrate 2 and a select gate 13 formed on the select gate oxide film 11, and connected in series with the memory transistor; and a peripheral circuit transistor having a peripheral circuit gate oxide film 23 formed on the substrate 2, and a peripheral circuit gate 25 formed on the peripheral circuit gate oxide film 23. The impurity concentration of the polysilicon of the floating gate 15 is lower than the impurity concentration of the polysilicon of the peripheral circuit gate 25. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
