The Behaviors of Alkaline Slurry during the CMP of TSV Backside Heterogeneous Microstructure. (1st January 2018)

• Record Type: Journal Article
• Authors: Wang, Bingquan; Liu, Yuhong; Cheng, Jie; Rao, Can; Lu, Xinchun
• Is Part Of: ECS journal of solid state science and technology. Volume 7:Number 2(2018)
• Page Start: P15
• Page End: P23
• Publication Date: 2018-01-01
• Subjects: Backside chemical mechanical planarization -- Heterogeneous microstructure -- Through silicon via; Solid state chemistry -- Periodicals; Electronics -- Materials -- Periodicals; Electrochemistry -- Periodicals; 541.0421
• DOI: 10.1149/2.0011802jss
• Languages: English
• ISSNs: 2162-8777

Abstract

Abstract : In the integrated circuits industry, 3D integration technology has been extensively studied. Through silicon via (TSV) technology is the core technology of the 3D integration. Chemical mechanical planarization (CMP) process, due to its high ability to achieve local and global planarization, is introduced into the traditional 1 st back side via reveal (BVR) process during the back side thinning and flattening of TSV wafers. In this paper, CMP experiments were performed to study the selective removal of the back side TSV heterogeneous microstructure using alkaline slurry with hydrogen peroxide as oxidant. Atomic force microscope (AFM) measurements were used to evaluate the surface topography, and energy dispersive spectrometer (EDS) was used to characterize the surface chemistry. Scratch experiments were also conducted by AFM method to characterize the removal mechanism on the Cu surface during CMP. Based on the experimental results, the behaviors and mechanism of H2 O2, BTA and pH value in different CMP slurries were discussed. The results show that a slurry contains 0.3 wt%–0.6 wt% H2 O2, 15 mM of BTA and pH value of 10.5–11 is suitable to achieve a smooth polished surface. Findings in the research will have a guiding significance to the research of TSV back side CMP and BVR process.