| 摘要 |
PURPOSE: A method of manufacturing a semiconductor memory device is provided to prevent a short circuit between a bit line and a gate electrode in a postprocess by forming a transition metal layer as a second hardmask layer on a silicon nitride layer as a first hardmask layer. CONSTITUTION: A preliminary gate electrode structure including a gate insulating layer, a conductive layer(110), a first hardmask layer(115), and a second hardmask layer(120) having a transition metal is formed on a semiconductor substrate(100). A source/drain region is formed on the semiconductor substrate of both sides of the preliminary gate electrode structure. A buffer oxide layer(125) and a barrier nitride layer(130) are formed on the semiconductor substrate and the preliminary gate electrode structure. An interlayer dielectric(135) is formed on the barrier nitride layer. The interlayer dielectric is etched to expose the barrier nitride layer of the source/drain region and form a spacer on a sidewall of the preliminary gate electrode structure. A contact pad region is formed by etching the exposed barrier nitride layer. The conductive layer is buried to fill the contact pad region. A CMP process for the conductive layer is performed. A wet-etch process is performed to remove the residues of the second hardmask layer.
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