NOVELTY - Forming a first flowable matrix (220) on a solar cell (200), where the solar cell has a front side (202) which faces the sun during normal operation and a back side (204) opposite the front side, involves: forming a polished surface on a silicon substrate (210); and forming a first flowable matrix in an interdigitated pattern on the polished surface, where the interdigitated pattern comprises features of uniform thickness and width.    USE - For forming a first flowable matrix on a solar cell; and for fabricating the solar cell (claimed) such as back-contact solar cell, front-contact solar cell, monocrystalline silicon solar cell, polycrystalline silicon solar cell and amorphous silicon solar cell.    ADVANTAGE - The present method improves the printed line thickness and linearity of the solar cell.    DETAILED DESCRIPTION - Forming a first flowable matrix (220) on a solar cell (200), where the solar cell has a front side (202) which faces the sun during normal operation and a back side (204) opposite the front side, involves: forming a polished surface on a silicon substrate (210); and forming a first flowable matrix in an interdigitated pattern on the polished surface, where the interdigitated pattern comprises features of uniform thickness and width. Forming the polished surface on the silicon substrate comprises etching a silicon substrate using a chemical etchant selected from sulfuric acid, acetic acid, nitric acid, hydrofluoric acid and phosphoric acid. The first flowable matrix comprises a material selected from flowable amorphous silicon and a flowable polysilicon. INDEPENDENT CLAIMS are included for the following:    (1) fabricating the solar cell involving forming a polished surface on a silicon substrate using an etchant, where the polished surface has at most 500 nanometer peak-to-valley roughness and is formed on the back side of the solar cell; depositing first and second dopant material, each dopant material has a viscosity of 1-25 centipoise (cP), in an interdigitated pattern on the polished surface, and the first and second dopant materials comprise a first and second dopant source, respectively, where the polished surface allows the first and second dopant materials to form an interdigitated pattern comprising features of uniform thickness and width; heating the silicon substrate and the first and second dopant materials to a temperature sufficient to cause the first and second dopant sources to diffuse into the silicon substrate forming a first and second doped regions within the silicon substrate; depositing a first dielectric layer over the first and second doped regions; forming contact openings within the first dielectric layer; forming a first metal layer established through the contact openings over the first and second doped regions, where the first metal layer comprises electrically connected grids to the first and second doped regions on the back side; and forming a second metal layer on the first metal layer, where the first metal layer electrically couples the second metal layer to the first and second doped regions; and    (2) fabricating the solar cell involving forming a polished surface on a silicon substrate using an isotropic etchant; forming first and second doped regions on the back side of the solar cell; depositing a first dielectric layer over the first and second doped regions; forming several contact openings within the first dielectric layer; depositing a first metal paste (274) to at least fill at least one contact opening established through the dielectric layer formed over the first and second doped regions, where the topography of the first and second doped regions is conformal with the polished surface of the silicon substrate; depositing a second metal paste (276) to connect more than one contact opening filled with the first metal paste to form interdigitated patterns over the dielectric layer on the back side, where the second metal paste is deposited by industrial printing methods over the polished surface such that the topography of the second metal paste is conformal with the polished surface of the silicon substrate; curing the first and second metal paste to form a first metal layer comprising electrically connected grids to the first and second doped regions on the back side; and forming a second metal layer on the first metal layer, where the first metal layer electrically couples the second metal layer to the first and second doped regions.    DESCRIPTION OF DRAWING(S) - The figure shows cross-sectional representations of a solar cell being fabricated in accordance with the methods for forming a first flowable matrix on a solar cell.    Solar cell (200)    Front side of the solar cell (202)    Back side of the solar cell (204)    Silicon substrate (210)    First flowable matrix (220)    First metal paste (274)    Second metal paste (276)