A positive resist composition contains a novolak resin in which 3-27 mol % of
the
hydroxyl group hydrogens are substituted with 1,2-naphthoquinonediazidosulfonyl
ester groups, a methyl vinyl ether-monoalkyl maleate copolymer and optionally,
an alkali-soluble cellulose whose glucose ring substituent groups are substituted
with organic groups at a specific rate. The composition is useful as a thick film
photoresist which is subject to a plating step and offers many advantages including
high sensitivity, perpendicular geometry, high resolution, and crack resistance
during and after the plating step.
