Title: Slurry parameters effect on Chemical–Mechanical Planarisation (CMP) of deposited silver (Ag) on chips

Authors: Y.J. Dai, G.S. Pan, H.F. Pei, J.Z. Sun, Y. Liu, H. Du

Addresses: The State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, People's Republic of China. ' The State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, People's Republic of China. ' Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, People's Republic of China. ' The State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, People's Republic of China. ' Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, People's Republic of China. ' Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, People's Republic of China

Abstract: Ag-deposited chips composed of electrodes, which are spaced apart by photoresist, are polished by Chemical-Mechanical Planarisation (CMP). We optimise the polishing process parameters including processing pressure, rotating speed, slurry supplying rate, etc., and examine the effect of some slurry parameters such as abrasives, oxidisers, corrosives, complexing agents and surfactants and get optimum Ag CMP slurry with high Material Removal Rate (MRR) and low average roughness (Ra). Low vertical distance between Ag and photoresist is obtained by optimising metal Ag MRR and controlling polishing end-point exactly. CMP mechanism and relationship between surface defects and additives structures are elementary discussed too.

Keywords: silver CMP; process parameters; surface roughness; surface defects; CMP mechanisms; chemical-mechanical planarisation; silver deposition; additives; polishing parameters; processing pressure; rotating speed; slurry supply rate; slurry parameters; abrasives; oxidisers; corrosives; complexing agents; surfactants; material removal rate; MRR; Ag deposited chips; interconnect metallisation; integrated circuits.

DOI: 10.1504/IJSURFSE.2010.033251

International Journal of Surface Science and Engineering, 2010 Vol.4 No.3, pp.237 - 249

Available online: 14 May 2010 *

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