Chemical Mechanical Polishing of Inlaid Copper Structures with Ru/Ta/TaN as Barrier/Liner Layer. (27th October 2018)

• Record Type: Journal Article
• Authors: Cheng, Jie; Wang, Bingquan; Wang, Tongqing; Li, Changkun; Lu, Xinchun
• Is Part Of: ECS journal of solid state science and technology. Volume 7:Number 11(2018)
• Page Start: P634
• Page End: P639
• Publication Date: 2018-10-27
• Subjects: Films -- Surface Science -- barrier -- chemical mechanical polishing (CMP) -- ruthenium (Ru); Solid state chemistry -- Periodicals; Electronics -- Materials -- Periodicals; Electrochemistry -- Periodicals; 541.0421
• DOI: 10.1149/2.0121811jss
• Languages: English
• ISSNs: 2162-8777

Abstract

Abstract : Ru as a novel barrier/liner material for Cu interconnects, has gained application in the sub-10 nm technology node. In this paper, methods to polish patterned wafer with Ru/Ta/TaN tri-layers as liner/barrier have been proposed. Effects of pattern geometry and CMP variables (such as polishing down pressure and oxidant content) on polishing uniformity were fully investigated. Apart from this, interfacial defects after barrier polishing were comprehensive characterized by atomic force microscopy and transmission electron microscopy methods. Results show that hydrogen peroxide (H2 O2 ) is effective in the mutual material removal of Cu/Ru/Ta/TaN/BD1 heterogeneous materials. Good surface quality could be obtained by using proper CMP process, with Cu dishing of 604.1 Å for the 100/100 μm array.