Image Number 4 for United States Patent #8129099.
Double patterns are formed by coating a first chemically amplified positive resist composition comprising an acid labile group-bearing resin and a photoacid generator and prebaking to form a resist film on a processable substrate, exposing the resist film to high-energy radiation, PEB, and developing with an alkaline developer to form a first positive resist pattern, treating the first resist pattern to be alkali soluble and solvent resistant, coating a second resist composition and prebaking to form a reversal film, and exposing the reversal film to high-energy radiation, PEB, and developing with an alkaline developer to form a second positive resist pattern. The last development step includes dissolving away the reversed first resist pattern and achieving reversal transfer.
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