| 摘要 |
<p>PURPOSE: To provide a nonvolatile semiconductor storage device wherein punch through between neighboring memory element parts is restrained, without deteriorating memory cell area reduction. CONSTITUTION: Source lines and bit lines are arranged in parallel on a substratum 1. A plurality of memory element parts are adjacently arranged between the lines. Trenches 20 are formed between the adjacent memory element parts, which are isolated by the trenches 20. A floating gate layer, a second insulating layer and a control gate layer are etched by using a mask, and a floating gate 14, a second insulating film 15 and a control gate 16 are formed by patterning. The trenches 20 are formed between the drain regions and the source regions of the substratum 1 by performing etching in the self-alignment manner using a mask 13.</p> |
