Evaluation and de-coupling of electrochemical and mechanical effects of diluted WCMP commercial slurry on tungsten removal rate

Conference: ICPT 2007 - International Conference on Planarization / CMP Technology
10/25/2007 - 10/27/2007 at Dresden, Germany

Proceedings: ICPT 2007

Pages: 6Language: englishTyp: PDF

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Gianni, Davide M.; Spinolo, Giulia (Advanced R&D - Flash Memories Group, STMicroelectronics S. r. I, Via C.Olivetti 2, 20041 Agrate Brianza, Italy)
Gianni, Davide M.; Masciocchi, Norberto; Maspero, Angelo (Dipartimento di Scienze Chimiche ed Ambientali, Universita dell'Insubria, Via Valleggio 11, 22100 Como, Italy)
Mazzarolo, Alice; Vicenzo, Antonello (Dipartimento di Chimica, Materiali, Ingegneria Chimica "Giulio Natta", Politecnico di Milano, Via Mancinelli 7, 20131 Milano, Italy)

Electrochemical properties and removal rates of modified commercial WCMP slurries have been evaluated. Primarily, the influence of the pH and degree of dilution on the open circuit potential and corrosion current density of CVD tungsten film was investigated. CMP removal rate were measured under the same set of conditions. Relevant aspects of the electrochemical behaviour are highlighted and related to the polishing behaviour. The results of this study are relevant to the operative management of the WCMP process and corroborate the starting working principle that ex-situ characterization of basic parameters is a useful procedure for WCMP optimization.