| 摘要 |
PURPOSE: To obtain a memory cell very small in size and large in capacity by a method wherein an element region inside a semiconductor substrate is isolated by an element isolation region, and gate electrodes are formed on an element region. CONSTITUTION: A gate insulating film 21 is formed on a semiconductor substrate 20, and a polycrystalline silicon film 22, which is turned to a gate electrode is formed on the gate insulating film 21. An etching mask material 23 is formed on the polycrystalline silicon film 22, and a part of the semiconductor substrate 20 is etched as deep as required to serve as an element isolation region or an element isolation groove 25. An insulating film 26 is formed on all the surface to fill up the element isolation groove 25. Then, the insulating film 26 and the mask material 23 are removed, an element isolation region 25a is formed, then the polycrystalline silicon film 22 is removed using a resist film as a mask, and a gate electrode 22a is formed. |
