| 摘要 |
<p>A flash memory device and a manufacturing method thereof are provided to prevent increase of critical dimension of a floating gate by using a hafnium aluminium oxide layer made of a high-k material. A first electrode layer(33) for a floating gate is formed. A dielectric is formed on the first electrode layer. A lower dielectric(34), a hafnium aluminium oxide layer(35), an upper dielectric(36) are sequentially laminated to form the dielectric. A second electrode layer for a control gate is formed on the dielectric. The second electrode layer and the upper dielectric are etched. The hafnium aluminium oxide layer is wet-etched. The lower dielectric and the first electrode layer are etched. The wet etching is performed until the hafnium aluminium oxide layer is sufficiently etched to form a vertical profile. The wet etching is performed with DHF(Diluted HF).</p> |
