摘要 |
A chemically amplified positive resist composition contains as a base a carboxyl or phenolic hydroxyl group-containing resin soluble in aqueous alkaline solution, in which acid labile groups are incorporated into at least some of the hydrogen atoms on the carboxyl or phenolic hydroxyl groups so that the resin becomes insoluble or substantially insoluble in alkali, wherein the resin contains acid labile groups of at least two types, acid labile groups of one type are acetal or ketal groups, and acid labile groups of the other type are tertiary hydrocarbon groups or tertiary hydrocarbon group-containing substituents. The resist composition remains stable during vacuum standing after exposure to electron beams or soft x-rays, leaves minimal footings on chromium substrates, has an excellent sensitivity and resolution, and is thus suited as a micropatterning material for use in the processing of mask substrates.
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