Use of methanofullerne derivatives as resist materials and method for forming a resist layer

Abstract

The use as a resist material of a methanofullerene derivative having a plurality of open-ended addends, and to a method for forming a patterned resist layer on a substrate using the methanofullerene derivatives. The methanofullerene derivatives can be represented by the formal C(CRR)where x is at least 10, m is at least 2, each addend represented by CRRis the same or different, and wherein each Rand Ris each a monovalent organic group, or a divalent organic group which forms a ring structure by being joined to the fullerene shell, or where both Rand Rof an addend are divalent groups, they may be mutually joined to form a ring structure, save that at least two of Ror two of Rare monovalent, or a mixture of such derivatives. The use of any methanofullerene derivative which has been chemically amplified for formation of a patterned resist layer. The essential step of the method is forming a coating layer comprising the methanofullerene derivative on the substrate surface, the methanofullerene derivative being chemically amplified by including in the coating layer at least one additional component which increases the sensitivity of the exposed layer to actinic radiation which is subsequently used to pattern the layer.