| 摘要 |
PROBLEM TO BE SOLVED: To provide a cell array region and the formation method of a NOR type mask ROM device. SOLUTION: A plurality of word lines WL1', WL2', WL3' are formed side by side on a semiconductor substrate, and a plurality of sub bit lines SBL1', SBL2' SBL3', SBL4' are formed to orthogonally cross the word lines WL1', WL2', WL3' on the upper part of the word lines WL1', WL2', WL3'. A trench region is formed on the semiconductor substrate exposed by the word lines WL1', WL2', WL3' and the sub bit lines SBL1', SBL2', SBL3', SBL4'. An interlayer insulation layer is formed over the entire plane, after the trench region is formed, and the bit lines BL1', BL2' are formed side by side on the interlayer insulation layer. |
