Dielectric isolation in the bit-line direction is performed by a first trench filled with an insulator, dielectric isolation in the word-line direction is performed by a second trench filled with a conductive film serving as a field-shield electrode interposing an insulating film, and capacitors are formed on side walls of the second trench by the conductive film and a semiconductor substrate with the insulating film interposed therebetween. A high-density, large-scale DRAM is realized by combin...









