Fabrication of a metalized blind via

Abstract

A method and structure for forming a metalized blind via. A dielectric layer is formed on a metallic layer, followed by laser drilling a depression in the dielectric layer such that a carbon film that includes the carbon is formed on a sidewall of the depression. If the laser drilling does not expose the metallic layer, then an anisotropic plasma etching, such as a reactive ion etching (RIE), may be used to clean and expose a surface of the metallic layer. The dielectric layer comprises a dielectric material having a carbon based polymeric material, such as a permanent photoresist, a polyimide, and advanced solder mask (ASM). The metallic layer includes a metallic material, such as copper, aluminum, and gold. The carbon film is in conductive contact with the metallic layer, and the carbon film is sufficiently conductive to permit electroplating a continuous layer of metal (e.g., copper) directly on the carbon film without need of an electrolessly plated layer underneath the electroplated layer. The laser drilling is accomplished using a laser radiation having a wavelength between about 180 nanometers and about 600 nanometers. The depression may have any cross-sectional shape and any spatial distribution of depths. As an example, the depression may include a blind via, then the blind via may have any cross-sectional shape, such as circular or non-circular, a rectangular channel, or a combination thereof.