| 摘要 |
PURPOSE: A method of forming a metal line of a flash memory device is provided to prevent cross talk between adjacent metal lines and to enhance RC delay by securing CD(Critical Dimension) gain of a trench oxide layer and photoresist margin using a contact first dual damascene manner. CONSTITUTION: An interlayer dielectric with a contact hole(47) is formed on a semiconductor substrate(41). The interlayer dielectric is composed of a contact hole oxide layer(43) and a trench oxide layer(45). A bottom photoresist layer, an intermediate material layer and a top photoresist pattern are sequentially formed thereon. An intermediate material pattern(52P) is formed by performing a first etching process on the intermediate material layer using the top photoresist pattern as an etching mask. A trench mask pattern is completed by forming a bottom photoresist pattern(51P) using a second etching process. A plurality of trenches are formed by performing a third etching process on the trench oxide layer using the trench mask pattern as an etching mask.
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