Characterization of an integrated multibeam laser mask-pattern generation and dry-etch processing total solution

摘要

As mask specifications continually tighten with the ever-present progression of Moore's law, mask manufacturing specifications have become increasingly difficult to achieve. Global process optimization from coat to etch is critical for achieving the required mask performance. As an Applied Materials company, Etec is in a unique position within the maskmaking industry to introduce mask manufacturing solutions that are optimized across a number of process steps. Working with the Applied Materials photomask etch team, Etec's laser mask-patterning product group characterized and implemented an integrated process recipe for the deep ultraviolet (DUV), raster-scan, continuous-wave, laser mask-patterning ALTA~(~R) 4000 system and the Applied Materials Tetra~(TM) Photomask Etch System. Using a photomask recipe already developed by Etec, commercially manufactured DX1100P photoresist-coated masks were patterned on the ALTA 4000 system, the latest optical pattern generator released by Etec Systems, and were subsequently used for integrating a dry-etch process with the Centura Photomask Etch system. The newly developed photomask process solution includes an anti-reflective resist top coat (patent pending), post-exposure bake (PEB), develop, dry etch, and resist strip steps. The areas investigated to optimize dry etch included partial pressure and flow rates of reactant gases, chamber pressure, overetch, and focus ring geometry. The characterization primarily focused on those parameters directly affecting the productive yield of the maskmaker, including critical dimension (CD) mean error, CD uniformity, process bias, selectivity, and micro-loading. This paper documents the results of Etec's implementation and characterization of an integrated mask manufacturing process, which is optimized across many process steps, creating a Total Solutions~(TM) concept for maskmaking.