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Supercomformal Filling Composition and Superconformally Filling a Recessed Feature of a Article

Patent Number: 10,889,908

Abstract

Superconformally filling a recessed feature includes: contacting the recessed feature with superconformal filling composition that includes: Au(SO3)23− anions; SO32− anions; and Bi3+ cations; convectively transporting Au(SO3)23− and Bi3+ to the bottom member of the recessed feature; subjecting the recessed feature to an electrical current to superconformally deposit gold from the Au(SO3)23− on the bottom member relative to the sidewall and the field, the electrical current providing a cathodic voltage; and increasing the electrical current subjected to the field and the recessed feature to maintain the cathodic voltage between −0.85 V and −1.00 V relative to the SSE during superconformally depositing gold on the substrate to superconformally fill the recessed feature of the article with gold as a superconformal filling of gold, the superconformal filling being void-free and seam-free.

Patent Description

This invention disclosure details a process for filling trenches and vias with gold so that they can be used for interconnects in microelectronics. The process fills the features preferentially from the bottom, permitting seam-free and void-free filling. Gold is deposited almost exclusively within the recessed features, with minimal deposition on the field, minimizing waste and reducing post­ deposition processing time. The electrolyte includes no lead-based additives as well as no polymer additives. The electrolyte is non-cyanide and nearly neutral. Deposition is conducted at room temperature.

The figure below shows (panels A and B) sub-conformal fillings, (panel C) a conformal filling; and (panels D and E) superconformal fillings.

Features

Gold is deposited almost exclusively within the recessed features, with minimal deposition on the field, minimizing waste and reducing post­ deposition processing time. The electrolyte includes no lead-based additives as well as no polymer additives.

Created February 16, 2021