Fabrication of a metalized blind via

• Main Authors: Egitto, Frank D, Foster, Elizabeth, Galasco, Raymond T, Houser, David E, Janecek, Mark L, Kindl, Thomas E, Knight, Jeffrey A, MacQuarrie, Stephen W, Markovich, Voya R, Matienzo, Luis J, Rai, Amarjit S, Russell, David J, Wike, William T
• Format: Patent
• Language: English
• Published: 10.06.2003

1. Technical Field 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 includes 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, a rectangular channel, or a combination thereof.