Silicon Integrated Systems Corporation

Jen-Hann Tsai

Chen-Chiu Hsue

Shyh-Dar Lee

A metal capacitor in damascene structures is provided. A first Cu wire and a second Cu wire are located in a first insulator. A first sealing layer is located on the first and the second Cu wires. A second insulator is located on the first sealing layer. A third insulator is located on the second insulator, and acting as an etch stop layer. A first Cu plug and a second Cu plug are located in the first sealing layer, the second insulator and the third insulator. A capacitor is located on the third insulator and the first Cu plug, the capacitor having an upper electrode, a capacitor dielectric and a bottom electrode with the same pattern each other, wherein the bottom electrode is connected to the first Cu wire through the first Cu plug. A conducting wire is located on the third insulator and the second Cu plug, wherein the conducting wire is connected to the second Cu wire through the second Cu plug. A fourth insulator is located on the conducting wire. A fifth insulator with a flat surface is located on the upper electrode, the fourth insulator and the third insulator. A plurality of dual damascene structures including a third plug, a fourth Cu plug, a third Cu wire and a fourth Cu wire are located in the fifth insulator, wherein an upper electrode of the capacitor is connected to the third Cu wire through the third Cu plug, and the conducting wire is connected to the fourth Cu wire through the fourth Cu plug. A second sealing layer is located on the third and fourth Cu wires.

Metal capacitor in damascene structures

A method for forming a metal capacitor in a damascene process is provided. Before the metal capacitor is formed, the underlying interconnections are fabricated with Cu metal by damascene processes. The capacitor is formed by depositing a first metal layer, an insulator and a second metal layer. The stacked layers are then subjected to a masking process and an etching process to form the thin-film capacitor and the metal wire with the remaining insulator and the remaining second metal layer thereon. The remaining second metal layer located on the metal wire is removed by another masking process and another etching process. After forming the capacitor and the metal wire, the upper interconnections are fabricated with Cu metal by damascene processes.

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Tainan, Taiwan

Jen-Hann Tsai