Large-area ICs (e.g., silicon wafer-based solar cells) are produced by positioning a mask between an extrusion head and the IC wafer during extrusion of a dopant bearing material or metal gridline material. The mask includes first and second peripheral portions that are positioned over corresponding peripheral areas of the wafer, and a central opening that exposes a central active area of the wafer. The extrusion head is then moved relative to the wafer, and the extrusion material is continuously extruded through outlet orifices of the extrusion head to form elongated extruded structures on the active area of the wafer. The mask prevents deposition of the extrusion material along the peripheral edges of the wafer, and facilitates the formation of unbroken extrusion structures. The mask may be provided with a non-rectangular opening to facilitate the formation of non-rectangular (e.g., circular) two-dimensional extrusion patterns.