Method of depositing metallic layers based on nickel or cobalt on a semiconducting solid substrate; kit for application of said method

摘要

The present invention relates to a kit intended for the deposition of nickel or cobalt in the cavities of a semiconductor substrate intended to form through-silicon vias (TSV) for making interconnections in integrated circuits in three dimensions.;The invention also relates to a method of metallization of the insulating surface of such a substrate which comprises contacting the surface with a liquid aqueous solution containing:
at least one metal salt of nickel or cobalt;at least one reducing agent;at least one polymer bearing amine functions, andat least one agent stabilizing the metal ions.;The step coverage of the layer of nickel or cobalt obtained can be greater than 80%, which facilitates subsequent filling of the vias with copper by electrodeposition.

主权项

1. A method of electroless coating of a silicon substrate, covered with a layer of an electrically insulating material, and having a collection of cavities suitable for forming through-vias useful for the fabrication of integrated circuits in three dimensions, said method comprising coating the insulating surface of said cavities with a metallic layer that forms a barrier to the diffusion of copper and comprises a material based on nickel or cobalt,
wherein the method comprises contacting the insulating surface of said cavities with an aqueous solution comprising:
at least one metal salt of nickel or cobalt ions, at a concentration between 10−3 M and 1 M;at least one reducing agent of the nickel or cobalt ions, at a concentration between 10−4 M and 1 M;optionally, at least one stabilizer of the nickel or cobalt ions; andat least one polymer bearing amine functions, at a concentration in the range from 5 to 250 mg/l, at a temperature between 50° C. and 90° C., for a time between 30 s and 30 min, to form a metallic layer having a thickness of at least 6 nanometers at the bottom of the cavities, and subsequent to the step of formation of the barrier layer, filling the cavities with copper without having first formed a copper seed layer on the surface of the barrier layer.