All-dry bilayer lithography

The very first chemical amplification resist designed for use in bilayer lithography employed Si-containing polyphthalaldehyde as a top layer resin, 

Poly[4,5-bis(trimethylsilyl)phthalaldehyde] has been used in a similar all-dry process to etch a 2 pm-thick polyimide film [440]. 

Acid-catalyzed hydrolysis of poly(4-trimethylsilyloxystyrene) was employed in the design of an aqueous base developable positive resist as described earlier 

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Fig. 155 All-dry bilayer lithography (thermal development-02 RIE pattern transfer)...

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