| 摘要 |
PURPOSE:To obtain the non-volatile semiconductor memory which has good memory retaining properties and a long life and enables an increase of writing efficiency and an enhancement of integration and further in which variation is reduced and an improvement of the yield is possible by using the oxide film formed by thermal oxidation of polycrystalline Si which is controlled the impurity concentration for the insulating film on the floating gate electrode. CONSTITUTION:When a voltage is applied in a manner the control gate electrode 15 is positive to the N type semiconductor substrate 11, if the voltage is enough high, the electrons are stored in a floating gate electrode 13 with passing through the insulating film 12 to memory the information. At this time, as the insulating film 14 consists of the insulating film of SiO2 formed by thermal oxidation of polycrystalline Si which is controlled its impurity concentration by ion implantation, this non-volatile semiconductor memory has good insulating properties, good memory retaining properties and a long life. Also, in the manufacture, the ion implantation does not need a strict control of a temperature or a gas flow as in the thermal diffusion so that the variation caused by the oxide film of polycrystalline Si can be restricted and the yield is improved. |
