| 摘要 |
PURPOSE:To prevent the step cut of wirings by reducing stepwise differences at gate regions by a method wherein the burial position for a floating gate is determined by removing an oxide film which is formed at the same time as a field oxide film. CONSTITUTION:The field oxide films 22 are formed selectively on the surface of a P type substrate 21, and a source and drain regions 23 and 24 are formed at regions whereon the films 22 are not formed. At this time, the thick oxide film 43 is formed simultaneously at a gate forming scheduled region. Next, a recess 44 is formed by removing the film 43. A gate oxide film 25 is formed at the recess 44, and a polycrystalline Si film 45 thereon, resulting in the floating gate 27. After forming a control gate 28 on the gate 27 and then a phospho-silicate glass layer 30, aluminum electrodes 31 are formed on the regions 23 and 24 and the gate 28. |
