| 摘要 |
Methods for fabricating semiconductor devices are disclosed. An illustrated method includes: etching a semiconductor substrate to form a trench, forming an ONO film on the semiconductor substrate, removing the ONO film from the upper surface of the semiconductor substrate while leaving the ONO film on an inside wall surface of the trench, forming a gate oxide film on the semiconductor substrate adjacent the ONO film, depositing polysilicon on the semiconductor substrate, and selectively removing the polysilicon to form SONOS gate electrodes on the gate oxide film and the trench, respectively. Because opposite sides of the polysilicon gate electrode are covered with an ONO layer, the size of the nitride film may be substantially maximized.
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