Electrochemical Deposition in Deep Vias

Abstract

Copper is used as interconnects on chips. It is laid down in deep vias by electrodeposition. For the simple case, the rate of electrodeposition on the shoulders is much greater than that at the bottom, and the via-mouth closes during the process and a bubble is captured inside. Approximate solutions to the electrodeposition process, when the transport is diffusion controlled and when it is reaction controlled, are obtained. It is shown that bubbles are easily captured in diffusion-controlled systems, but no bubbles are captured in the reaction-controlled system. However, the diffusion-controlled system has very low currents, low electrodeposition rates, and low production rates, and the reaction-controlled system has even lower rates. Based on these, the existing solutions to the bubble-capture problem are briefly reviewed to suggest that inducing natural convection appears most promising.

Department(s)

Chemical and Biochemical Engineering

Keywords and Phrases

Deposition Methods; Electrochemical Deposition; Superfill; Trenches

International Standard Serial Number (ISSN)

1547-5905

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2006 Wiley Interscience, All rights reserved.

Publication Date

01 Jan 2006

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