Optimization of microvia-technology using excimer laser for build-up layer application in microelectronics

In interconnection microelectronics microvias play a key role in the manufacture of high-density circuitry for use in electronic systems such as portable, smart sensors and computing applications. In the current work an excimer laser is used and microvias in the dielectric of the build-up layer are generated with the mask imaging method. Different laser parameters (demagnification factor, energy transmission percentage, fluence) are optimised in order to obtain microvias with different diameters, taper angle and aspect ratio. With electrochemical Cu-deposition interconnections between the upper and the underlying circuitry are realised. A nearly uniform thickness of the plated copper is obtained, and quality of the plating is assessed by means of the degree of delamination of the electrochemically deposited copper.