Abstract: In an electrical via structure and fabrication method that is particularly suited to coplanar contact solar cells, an initial opening (38,48a,48b,64) through the substrate is coated and substantially closed with a dielectric material (42,52,80). An inner opening (44) is then formed through the dielectric, and the via is provided with a conductive coating (46,54). The dielectric is initially applied in a liquid state and is thereafter cured to a solid. The need for strong chemical etchants to smooth the via opening prior to application of the dielectric and metallization is eliminated, and a polyimide dielectric on a GaAs/Ge solar cell has resulted in a substantial improvement in leakage resistance and cell efficiency.