| 摘要 |
PROBLEM TO BE SOLVED: To prevent deterioration in a charge holding service life, and establish compatibility between the improvement of the cycling capability and the improvement of a circuit operation speed. SOLUTION: A floating gate 4 is formed on a sense transistor region of a p<SP>-</SP>-type Si substrate 1. In this case, the phosphorous concentration of a portion contacting a tunnel film 7 is set at a concentration which a phosphate is not precipitated. After that, an insulating film 8 is formed from the surface of the floating gate 4 to a selective transistor region of the p<SP>-</SP>-type Si substrate 1. In this case, a film having moisture resistance and dielectric constant higher than those of an oxide film such as a nitride film and an oxynitride film is used as the insulating film 8. After that, a gate electrode 9 of the selective transistor is formed. In this case, the phosphate concentration of the gate electrode 9 is set at higher than that of a portion contacting the tunnel film 7 of the floating gate 4. Also, a conductive film for covering the floating gate 4 and shielding the potential of the floating gate 4 of a fixed potential is formed on the surface of an insulating film 8a of the sense transistor. COPYRIGHT: (C)2007,JPO&INPIT
|
