| 摘要 |
<p>A method for fabricating a flash device is provided to prevent the edge part of a gate oxide layer from being locally thickened by avoiding generation of a bird's beak under a cell control gate. A bottom oxide layer(210), a silicon nitride layer(230) and a top oxide layer(250) are sequentially deposited on a semiconductor substrate(100) including a cell region and a peripheral circuit region. A layer for a cell control gate(300) is deposited on the top oxide layer. A cap layer(400) is formed on the cell control gate. The cap layer and the cell control gate layer are patterned to form a cell control gate. An ion implantation process is performed to control the threshold voltage of a channel under the cell control gate. The bottom oxide layer, the silicon nitride layer and the top oxide layer that are formed on the peripheral circuit region of the substrate are selectively removed. A gate oxide layer is formed on the semiconductor substrate exposed by the removal of the bottom oxide layer, the silicon nitride layer and the top oxide layer by a dry oxide process. The gate oxide layer is made of an HTO(high temperature oxide) layer.</p> |
