NONVOLATILE SEMICONDUCTOR MEMORY AND FABRICATION NETHOD THEREFOR

文件类型：PDF文档
文件大小：374K
PROBLEM TO BE SOLVED : To provide a nonvolatile semiconductor memory having proper cell operation characteristics, by suppressing impairment of film quality resulting from a post-heating process, when a rare earth oxide, a rare earth nitride or a rare earth oxinitride containing a rare earth element is employed as an inter-electrode insulating film or a block insulating film, thereby avoiding crystallization or deterioration in the permittivity. SOLUTION : When an inter-electrode insulating film or a block insulating film containing one kind or more of first rare earth element and one kind or more of second element selected from among Al, Ti, Zr, Hf, Ta, Mg, Ca, Sr, and Ba is used, the compositional ratio of the first to second elements (number of atoms of the first element/number of atoms of the second element) is set low on a side touching a floating gate electrode or a charge storage layer and is set high on the side touching a control gate electrode, in such a way that the ratio changes continuously. COPYRIGHT : (C)2008, JPO&INPIT