摘要 |
This method comprising a stop layer, a dielectric layer, a bottom hard layer and top hard mask layer are formed on a substrate, sequentially. A via pattern photoresist layer is formed on the top hard mask layer. The top hard mask layer is etched by using the via pattern photoresist layer as a mask to transfer the via pattern into the top hard mask layer then removed the via pattern photoresist layer. A trench pattern photoresist layer is formed on the top hard mask layer wherein the trench pattern is over the via pattern. The bottom hard mask layer is etched by using the top hard mask layer as a mask to transfer the via pattern into the bottom hard mask layer. The top hard mask layer is etched by using the trench pattern photoresist layer as a mask, wherein the via pattern is transferred into a portion of the dielectric layer. The bottom hard mask layer is etched by using the top hard mask layer as a mask, wherein the via pattern is transferred into the dielectric layer. The dielectric layer is etched by using the bottom hard mask layer as a mask to form a via hole and a trench line in the dielectric layer, wherein the trench line is over the via hole, and the via hole exposes a portion of the substrate.
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