. The pillars 00 arranged in a matrix configuration are formed because the portion from the stopper layer 00 to the upper portion 00b of the word line member 00 already is divided by the trenches 00. On the other hand, the lower portion 00a of the word line member 00 is not divided by the trenches 00 and forms interconnects extending in the word line direction.  [0000] Then, the insulating material 00 is deposited on the entire surface. The insulating material 00 is filled into the trenches 00 and is deposited also on the upper face of the stopper layer 00. 