| 摘要 |
A method for fabricating a semiconductor device is provided to simplify a fabricating process by eliminating the necessity of a process for forming a photoresist layer in the lower part of a contact hole before a trench is etched. A lower interconnection(115) is formed on a semiconductor substrate. An interlayer dielectric(140) is stacked on the lower interconnection. A sub layer(143) having etch selectivity with respect to the interlayer dielectric, a first sacrificial layer(145) having etch selectivity with respect to the sub layer, and a second sacrificial layer(147) having etch selectivity with respect to the first sacrificial layer are sequentially formed on the interlayer dielectric. The second sacrificial layer is made of the same material as the sub layer, thicker than the sub layer. A mask pattern for forming a contact hole is formed on the second sacrificial layer, and the second sacrificial layer, the first sacrificial layer, the sub layer and the interlayer dielectric are etched to remove a predetermined thickness of at least the interlayer dielectric. A mask pattern(165) for forming a trench(175) is formed in the substrate, and the second and first sacrificial layers in a trench region is etched. The mask pattern for forming the trench is removed, and the sub layer exposed to the trench region is etched wherein a predetermined thickness of the second sacrificial layer is left. The interlayer dielectric is etched by using the residual second sacrificial layer as an etch mask so that at least part of the lower interconnection is exposed.
|
