Dual damascene structure and method

A method of fabricating a semiconductor device, the method comprising:

• disposing a workpiece in a processing chamber,
• disposing a first dielectric material over the workpiece, while said workpiece is in said processing chamber;
• disposing a second dielectric material over the first dielectric material, the second dielectric material comprising a different material than the first dielectric material, wherein the first dielectric material and the second dielectric material comprise a first insulating layer;
• depositing a hard mask over the second dielectric material, the depositing of said hard mask comprising depositing a first mask layer, depositing a second mask layer over said first mask layer and depositing a third mask layer over the second mask layer;
• forming a first pattern in the first dielectric material;
• cleaning the processing chamber while the workpiece remains in the processing chamber, and before removing any of the layers of the material on the workpiece;
• forming a second pattern different from the first pattern in the second dielectric material wherein forming said patterns comprises;
• patterning at least the third mask layer with the second pattern;
• patterning the third mask layer, the second mask layer and the first mask layer with the first pattern;
• transferring the first pattern to the second dielectric material;
• removing the third mask layer, the second mask layer and the first mask layer in the second pattern regions;
• transferring the first pattern to the first dielectric material;
• and
• removing the second dielectric material in the second pattern regions, subsequent to said step of cleaning.