Dual-Damascene is a process technology used to manufacture metal interconnects in integrated circuits. It is a further development of the Damascus process. By forming through holes and grooves at the same time in the same process step and filling them with metal, the integrated manufacturing of metal interconnects is realized.
Why is it called Damascus?
The city of Damascus is the capital of Syria, and Damascus swords are famous for their sharpness and exquisite texture. A kind of inlay process is required: first, the required pattern is engraved on the surface of Damascus steel, and the pre-prepared materials are tightly inlaid into the engraved grooves. After the inlay is completed, the surface may be a little uneven. The craftsman will carefully polish it to ensure the overall smoothness. And this process is the prototype of the dual Damascus process of the chip. First, grooves or holes are engraved in the dielectric layer, and then metal is filled in them. After filling, the excess metal will be removed by cmp.
The main steps of the dual damascene process include:
▪ Deposition of dielectric layer:
Deposit a layer of dielectric material, such as silicon dioxide (SiO2), on the semiconductor wafer.
▪ Photolithography to define the pattern:
Use photolithography to define the pattern of vias and trenches on the dielectric layer.
▪ Etching:
Transfer the pattern of vias and trenches to the dielectric layer through a dry or wet etching process.
▪ Deposition of metal:
Deposit metal, such as copper (Cu) or aluminum (Al), in vias and trenches to form metal interconnects.
▪ Chemical mechanical polishing:
Chemical mechanical polishing of the metal surface to remove excess metal and flatten the surface.
Compared with the traditional metal interconnect manufacturing process, the dual damascene process has the following advantages:
▪Simplified process steps: by forming vias and trenches simultaneously in the same process step, the process steps and manufacturing time are reduced.
▪Improved manufacturing efficiency: due to the reduction of process steps, the dual damascene process can improve manufacturing efficiency and reduce production costs.
▪Improve the performance of metal interconnects: the dual damascene process can achieve narrower metal interconnects, thereby improving the integration and performance of circuits.
▪Reduce parasitic capacitance and resistance: by using low-k dielectric materials and optimizing the structure of metal interconnects, parasitic capacitance and resistance can be reduced, improving the speed and power consumption performance of circuits.
Post time: Nov-25-2024