Simulation of Copper Electrodeposition in Millimeter Size Through-Silicon Vias

Published

December 16, 2020

Author(s)

Trevor Braun, Daniel Josell, Thomas P. Moffat

Abstract

Computational predictions of copper deposition in millimeter size through-silicon vias (mm-TSV) are presented based on localized breakdown of a co-adsorbed polyether-chloride suppressor layer. The model builds upon previous work on localized Cu deposition in microscale TSV and through-holes by incorporating 3D convective fluid flow calculations to more effectively evaluate chemical transport of cupric ion and additives, both of which are critical to adlayer formation and disruption within the via. Simulations using potentiostatic and potentiodynamic waveforms are compared to previously reported filling experiments. Alternatively, the utility of galvanostatic control and variations in fluid flow are explored computationally. For appropriate applied potential(s) or current deposition is localized to the via bottom, with subsequent growth proceeding in a bottom-up fashion. Selection of inappropriate current or potential waveforms, or convection conditions that supply insufficient cupric ion to the bottom of the via, results in prediction of voids. Simulations of deposition in via arrays (4×1) predict non-uniform growth across the arrays, with the passivation of individual vias associated with minor variations in convective flow and/or numerical noise in the simulation, that reflects the critical nature of the bifurcation process.

Citation

Journal of the Electrochemical Society

Pub Type

Journals

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Keywords

Forced Convection, Finite Element Method, Electronics Fabrication

Citation

Braun, T. , Josell, D. and Moffat, T. (2020), Simulation of Copper Electrodeposition in Millimeter Size Through-Silicon Vias, Journal of the Electrochemical Society, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=930972 (Accessed April 28, 2024)