| 摘要 |
PROBLEM TO BE SOLVED: To prevent a silicon substrate from being cut due to etching of counter-boring of an STI for increased reliability of a memory cell without increasing the number of photolithography steps. SOLUTION: Silicon oxide films 13, 25 and 26 as a gate insulating film and gate electrodes 6, 7 12a, and 12b such as a memory cell transistor 1 or the like are formed on a silicon substrate 3 (refer to (a) and (b).). A silicon oxide film 19 is formed on the entire surface of a cell to ensure the reliability of the cell, and it is peeled off from a contact surface and the surface of the gate electrode 12b of a high breakdown strength transistor 9. In this case, the silicon oxide film 26 as the gate insulating film and the STI 10 are etched at the same time. COPYRIGHT: (C)2006,JPO&NCIPI
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