Patent ID: 8192921
Filing Date: 2012-06-05
Classification: G03F

Abstract:
1. A process for forming a pattern by way of positive/negative reversal, comprising the steps of: coating a chemically amplified positive resist composition onto a processable substrate, the resist composition comprising a resin comprising recurring units of structure having acid labile groups which are eliminatable with acid, the resin turning to be soluble in an alkaline developer as a result of elimination of the acid labile groups, a photoacid generator capable of generating an acid upon exposure to high-energy radiation and optionally, a thermal acid generator capable of generating an acid upon heating, and an organic solvent, prebaking the coating to remove the solvent and to form a resist film, exposing the resist film to high-energy radiation through a phase shift mask having a lattice-like array of shifters, post-exposure baking so that the acid generated by the acid generator upon exposure acts on acid labile groups in the resin for thereby effecting elimination reaction of acid labile groups in the resin in exposed areas, developing the exposed resist film with an alkaline developer to form a positive pattern, illuminating or heating the positive pattern, the acid generated by illumination or the heat serving to eliminate acid labile groups in the resin in the positive pattern for thereby increasing the alkaline solubility of the resin and to induce crosslinks in the resin to such an extent that the resin does not lose solubility in an alkaline wet etchant, for thereby endowing the positive pattern with resistance to an organic solvent used in a reversal film-forming composition, coating a reversal film-forming composition on the positive pattern-bearing substrate to form a reversal film, and dissolving away the crosslinked positive pattern using an alkaline wet etchant.