Baths, methods, and tools for superconformal deposition of conductive materials other than copper

Abstract

Superconformal deposition promoters are used to facilitate the superconformal deposition of conductive metals other than copper. Features deposited using the baths, methods, and tools that employ the superconformal deposition promoters are void free. The superconformal deposition promoters include sulfonate terminated alkanethiols, sulfonic acid terminated alkanethiols, carboxylate terminated alkanethiols, carboxylic acid terminated alkanethiols, and sulfonate terminated alkanedisulfide compounds.

Description

FIELD OF THE INVENTION [0001] The present invention relates to the electrolytic deposition of conductive materials other than copper, such as gold into recessed features. BACKGROUND OF THE INVENTION [0002] Gold is used in the microelectronics industry as a conductive material to fill recessed features. Examples of recessed features include trenches and vias. Trenches filled with gold serve as conductive lines and vias filled with gold serve as interlayer interconnects. Decreasing the sizes of conductive features and thus the recessed features which are used to form such conductive features places rigorous demands on existing electroplating chemistry to completely fill the recessed features. The expense of gold places additional pressure on manufacturers to consistently achieve void-free fill of recessed features in order to achieve high yields. [0003] In certain situations, conventional baths are unable to form conductive features in recessed structures without voids that render the...

AI Technical Summary

Benefits of technology

[0004] The present invention provides bath compositions, methods and tools for achieving superconformal filling of recessed features with a conductive material other than copper, for example gold and silver. The baths and methods employ a superconformal deposition promoter selected from sulfonate terminated alkanethiols, sulfonic acid terminated alkanethiols, carboxylate terminated alkanethiols, carboxylic acid terminated alkanethiols, and sulfonate terminated alkanedisulfide compounds. The present inventors have observed that complete fill of recessed features and the demanding reentrant features can be achieved without other organic additives such as polyethylene glycol. In accordance with the present invention, complete fill is achieved at process conditions that device manufacturers find attractive.

[0008] Through the use of the compositions, methods and tools of the present invention, conductive materials can be deposited superconformally into small, e.g., submicron, recessed features at rates that microelectronic device manufacturers will find desirable. Device manufacturers will benefit from the increased productivity and yields achieved by the compositions, methods, and tools of the present invention.

Problems solved by technology

In certain situations, conventional baths are unable to form conductive features in recessed structures without voids that render the conductive features unsatisfactory for most applications.

Furthermore, manufacturers prefer not to use low deposition rates as they contribute to the cost of production.

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