Effects of H2O2 and pH on the Chemical Mechanical Planarization of Molybdenum. (24th September 2021)

• Record Type: Journal Article
• Authors: Ryu, Heon-Yul; Teugels, Lieve; Devriendt, Katia; Struyf, Herbert; Kim, Tae-Gon; Park, Jin-Goo
• Is Part Of: ECS journal of solid state science and technology. Volume 10:Number 9(2021)
• Publication Date: 2021-09-24
• Subjects: molybdenum -- CMP -- hydrogen peroxide -- chronoamperometry; Solid state chemistry -- Periodicals; Electronics -- Materials -- Periodicals; Electrochemistry -- Periodicals; 541.0421
• DOI: 10.1149/2162-8777/ac26d3
• Languages: English
• ISSNs: 2162-8777

Abstract

Abstract : The effects of H2 O2 on the chemical etching and removal rate (RR) of molybdenum (Mo) were investigated. Static etch rate (SER) and chemical mechanical planarization (CMP) experiments were performed using H2 O2 -based slurries at different pH levels. X-ray photoelectron spectroscopy (XPS) and potentiodynamic polarization analysis showed the formation of Mo oxides by the reaction between Mo and H2 O2 . The Mo SER, which increased with H2 O2 concentration, supported the dissolution of Mo oxides through the formation of peroxo Mo complexes with H2 O2 . The CMP removal mechanism was demonstrated by comparing the CMP RR with and without silica abrasives. In addition, the Mo oxidation rate by H2 O2 on a millisecond time scale was characterized with chronoamperometry to explain different RRs at pH values ranging from 2 to 8. The CMP RR of Mo was high at pH 2 and pH 10; however, pH 2 showed a lower SER than pH 10, leading to lower surface roughness.