1. Direct metal etch of ruthenium for advanced interconnect
- Author
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Nouredine Rassoul, Frederic Lazzarino, Daniele Piumi, Danny Wan, Sara Paolillo, and Zsolt Tőkei
- Subjects
010302 applied physics ,Plasma etching ,Materials science ,business.industry ,Process Chemistry and Technology ,Biasing ,02 engineering and technology ,Chemical vapor deposition ,Sputter deposition ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Atomic layer deposition ,Etching (microfabrication) ,0103 physical sciences ,Materials Chemistry ,Optoelectronics ,Deposition (phase transition) ,Wafer ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Instrumentation - Abstract
In this work, Ru wires patterning by direct etch are evaluated for a potential 5 nm technology node. The characteristics of Ru etching by varying the bias voltage, total flow rate and Cl2/(O2+Cl2) gas flow ratio are studied in an inductively couple plasma etching chamber. Ru sidewalls profile with a tapering angle of 90° and Ru to SiO2 hard mask etch selectivity of 6 are achieved. The authors show the feasibility of patterning lines with an aspect ratio up to 3.5 and lines with a critical dimension down to 10.5 nm (with a 3σ line width roughness of 4.2 nm), which paves the way to further scaling of this approach. Finally, the authors present a study on Ru line roughness after patterning on 300 mm wafers. Here, they compare line roughness results of wafers where Ru is deposited with different deposition techniques, such as atomic layer deposition and plasma vapor deposition, and it is annealed after deposition at various temperatures.In this work, Ru wires patterning by direct etch are evaluated for a potential 5 nm technology node. The characteristics of Ru etching by varying the bias voltage, total flow rate and Cl2/(O2+Cl2) gas flow ratio are studied in an inductively couple plasma etching chamber. Ru sidewalls profile with a tapering angle of 90° and Ru to SiO2 hard mask etch selectivity of 6 are achieved. The authors show the feasibility of patterning lines with an aspect ratio up to 3.5 and lines with a critical dimension down to 10.5 nm (with a 3σ line width roughness of 4.2 nm), which paves the way to further scaling of this approach. Finally, the authors present a study on Ru line roughness after patterning on 300 mm wafers. Here, they compare line roughness results of wafers where Ru is deposited with different deposition techniques, such as atomic layer deposition and plasma vapor deposition, and it is annealed after deposition at various temperatures.
- Published
- 2018