| 摘要 |
The present invention provides a carbon based etch stop, such as a diamond like amorphous carbon, having a low dielectric constant and a method of forming a dual damascene structure. The low k etch stop is preferably deposited between two dielectric layers and patterned to define the underlying interlevel contacts/vias. The second or upper dielectric layer is formed over the etch stop and patterned to define the intralevel interconnects. The entire dual damascene structure is then etched in a single selective etch process which first etches the patterned interconnects, then etches the contacts/vias past the patterned etch stop. The etch stop has a low dielectric constant relative to a conventional SiN etch stop, which minimizes the capacitive coupling between adjacent interconnect lines. The dual damascene structure is then filled with a suitable conductive material such as aluminum or copper and planarized using chemical mechanical polishing.
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