Evolution of microstructure and electrical conductivity of electroless copper deposits on a glass substrate

• Published in: Thin solid films 2012-07, Vol.520 (19), p.6095-6099
• Main Authors: Cui, Xiaoyun, Hutt, David A., Conway, Paul P.
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts: preparations and properties; Chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Copper; COPPER RESOURCES; DEPOSITION; Deposition rate; ELECTRICAL CONDUCTIVITY; Electrical properties of specific thin films; Electrical resistivity; Electroless deposition; ELECTROLESS PLATING; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Evolution; Exact sciences and technology; General and physical chemistry; Glass substrate; GLASSES; Microstructure; MICROSTRUCTURES; MINERAL DEPOSITS; Physics; PLATING; Resistivity; SCANNING ELECTRON MICROSCOPY; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Thin film structure and morphology
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2012.05.068

This paper describes the evolution of the microstructure and conductivity of electroless copper deposition on a glass substrate for applications in electronics manufacture. The glass was activated using a (3-aminopropyl)trimethoxysilane pre-treatment followed by a Pd/Sn catalyst. Surface morphology of the deposited copper films was characterized using a dual beam focused ion beam field emission scanning electron microscope, and together with atomic force microscopy, showed clearly that the roughness and grain size tended to increase with the plating time. Film thickness measurements showed a high initial deposition rate, which slowed to a constant level as the thickness increased above 100nm. This corresponded with the resistivity of the films which decreased rapidly as the thickness increased from 20 to 100nm, but then remained largely stable at a level approximately twice that of bulk copper. ► Morphology of electroless Cu on glass characterized as a function of plating time. ► The deposition rate of electroless Cu varied with deposition time. ► The roughness and grain size of the Cu deposits increased with the plating time. ► The resistivity of Cu films was measured and related to changes in microstructure.