| 摘要 |
<p>Flash memory device is manufactured by etching gate oxide film for high voltage formed in a cell region and a low voltage region by forming photoresist patterns to expose the gate oxide film and performing a wet etching process using the photoresist patterns as an etching mask. The gate oxide film is removed by performing a cleaning process on the resulting structure. Manufacture of flash memory device involves forming a gate oxide film for high voltage on a whole surface of a semiconductor substrate (12) on which a cell region, a low voltage region and a high voltage region have been formed; and etching the gate oxide film for high voltage formed in the cell region and the low voltage region by a predetermined depth, by forming photoresist patterns to expose the gate oxide film and performing a wet etching process using the photoresist patterns as an etching mask. The gate oxide film is removed by performing a cleaning process on the resulting structure. The photoresist patterns are removed after the gate oxide film removal. A floating gate electrode and a control gate electrode are formed by sequentially forming a tunnel oxide film (14), a first polysilicon film (16), a second polysilicon film (18), a dielectric film (20), a third polysilicon film (22) and a metal silicide film (24) on the whole surface of the resulting structure, and the resulting structure is then patterned. Source and drain regions are formed by implanting ions using the gate electrodes as an ion implant mask.</p> |
