Nano-imprint lithography (NIL) tool for semiconductor manufacturing employs die-by-die alignment system. For semiconductor device manufacturing, precise alignment of template mark and wafer mark that is composed of various film stacks, is required to achieve good overlay accuracy. We have studied the relation of wafer stack structure and NIL alignment accuracy. Using FPA-1200NZ2C (Canon Corp.), we have evaluated imprint performance on the wafers with different stacks. In this paper, we describe (i) alignment performance of the state-of-the art NIL tool, (ii) simulation of NIL alignment mark signal, and (iii) capability of NIL alignment system for various wafer stack structure.
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