US Patent 9525099 Dual-mask arrangement for solar cell fabrication

An arrangement for supporting substrates during processing, having a wafer carrier with a susceptor for supporting the substrate and confining the substrate to predetermined position. An inner mask is configured for placing on top of the substrate, the inner mask having an opening pattern to mask unprocessed parts of the substrate, but expose remaining parts of the substrate for processing. An outer mask is configured for placing on top of the inner mask, the outer mask having an opening that exposes the part of the inner mask having the opening pattern, but cover the periphery of the inner mask.