| 摘要 |
PROBLEM TO BE SOLVED: To suppress low-voltage/low-electric field writing, writing under a low energy barrier in erasure and deterioration in erasure which tend to be caused even when the energy barrier is made high by making fine particulate sizes in a particulate layer inserted into a tunnel insulating film to improve memory holding. SOLUTION: A nonvolatile semiconductor memory has a charge storage layer 130 formed on a channel region 101 of a semiconductor substrate 100 through the tunnel insulating film 110 interposed. In the tunnel insulating film 110, a first particulate layer 121 containing first conductive particulates is provided on a channel side and a second particulate layer 122 containing second conductive particulates having a larger average particle size than that of the first conductive particulates is provided on a charge storage layer side; and an average valueΔE<SB>1</SB>of energy needed to be charged with one electron for the first conductive particulates is made smaller than an average valueΔE of energy needed to be charged with one electron for the second conductive particulates, and the difference betweenΔE<SB>1</SB>andΔE is made larger than thermal motion energy (k<SB>B</SB>T). COPYRIGHT: (C)2010,JPO&INPIT |
