| 摘要 |
PURPOSE:To avoid the reduction of the degree of integration due to a limit on production, and to improve yield and reliability by preventing the lowering of breakdown voltage between an impurity layer and a base body by utilizing self- matching technique. CONSTITUTION:SiO2 3 on an Si substrate 1 is coated with an Si3N4 mask 4, and a field oxide film 5 is formed through wet oxidation. A hole is bored to the Si3N4 4 and the SiO2, phosphorus is thermally diffused and an N layer 6 is shaped. When the Si3N4 4 is removed and a SiO2 thin-film 7 is formed onto the N layer 6 through self-matching, the thickness of the SiO2 3 is increased, and changed into SiO2 8. A floating gate electrode 9 by poly si to which phosphorus is doped is shaped selectively,and coats one parts of the SiO2 7, 8. The poly Si 9 is thermally oxidized and wrapped by SiO2 10, and a control gate electrode 11 by poly Si to which phosphorus is deoped is shaped selectively. According to this constitution, non-volatile memory action can be conducted by utilizing the condition of the changes of the floating gate electrodes 9, and the device having the high degree of integration and high reliability is obtained in excellent yield without being subject to the limit on production. |
